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1.
Local Reg Anesth ; 17: 39-47, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38650746

RESUMO

Background: Effective post-operative analgesia profoundly influences patient recovery and outcomes after caesarean delivery. The Transversus Abdominis Plane (TAP) block represents a potential alternative, potentially offering greater effectiveness than epidural analgesia while causing fewer adverse effects. Objective: To assess if the abdominal transverse block provides superior postoperative pain relief in patients undergoing caesarean delivery compared to epidural analgesia. Methods: Participants were divided into parallel groups: an experimental group receiving TAP block (n=25) and a control group receiving epidural analgesia (n=24). All patients received a 10 mg dose of hyoscine at the end of the surgery. Experimental Group received a total of 20 mL of 0.2% ropivacaine. In Epidural group received 0.2% ropivacaine at 4 mL/h for 24 hours. All participants were administered combined with neuroaxial block anesthesia. The patients selected for epidural analgesia received the mentioned dose, while the other group block had the epidural catheter removed after the cesarean section. The primary outcome was post-caesarean pain, evaluated using the Visual Analog Scale (VAS) at four intervals (0, 6, 12, and 24 hours). Also, surgical bleeding and residual motor were evaluated. VAS pain scores between the groups were compared using the Friedman test and Generalized Linear Model (GLM) for non-normally distributed data. The effect size was estimated with Eta Square ([Formula: see text]), considering values ≥0.38 as indicative of large effects. A two-tailed p-value < 0.05 was deemed statistically significant. Results: Statistically significant differences in pain scores were noted at 0 and 6 hours post-surgery (p<0.01). The TAP block group reported lower pain scores at 0 hours (mean=0.04) and 6 hours (mean=1.16) compared to the epidural group, reflecting a substantial effect size. Conclusion: The TAP block proves advantageous in mitigating postoperative pain for women post-caesarean delivery, particularly in the initial 6 postpartum hours. This relief promotes early mother-infant bonding and facilitates breastfeeding.

2.
Am J Trop Med Hyg ; 110(5): 971-978, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38507814

RESUMO

Dengue is the most common arboviral disease in the world. Traditionally, it has affected more adults, but the incidence in children has increased in recent years. Colombia is no stranger to this change; therefore, we aimed to find the differences in signs, symptoms, and clinical, hematological, and hemogram characteristics between children under 12 years old and individuals aged 12 years and older in an endemic region of Colombia in 2020-2022. The analyses were conducted with baseline data, corresponding to a cross-sectional design. Multiple correspondence analysis was used for general, dermatological, and clinical symptom profiles. Discriminant analysis was used for laboratory profiles. Multiple correspondence analysis was applied to nominal categorical data, employing Euclidean distances to analyze age groups. Discriminant analysis was applied to a training sample and validated on a test sample. The overall agreement of the model's discrimination, sensitivity, specificity, and fit indicators was calculated. The results indicated that individuals under 12 years exhibited distinct dermatological and clinical features, including rash, pruritus, hypotension, lymphocyte count, and platelet count, compared with those aged 12 years and older. In contrast, those 12 years and older were profiled for general and clinical symptoms such as pain (back pain, retro-orbital pain, headache), dizziness, chills, hematuria, tachypnea, and elevated/high hematocrit, hemoglobin, and basophil values. These findings are crucial to understanding the high incidence in children; they also facilitate rapid understanding of the disease in clinical care settings and differentiate it from other febrile outbreaks. This will affect disease control, particularly in severe cases, and reduce mortality.


Assuntos
Dengue , Humanos , Colômbia/epidemiologia , Criança , Dengue/epidemiologia , Dengue/diagnóstico , Adulto , Masculino , Feminino , Adolescente , Estudos Transversais , Pré-Escolar , Doenças Endêmicas , Adulto Jovem , Lactente , Pessoa de Meia-Idade
3.
J Interpers Violence ; 39(11-12): 2552-2575, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38149609

RESUMO

School violence and bullying are current and problematic events during adolescence. They are likely to have a marked presence in places highly exposed to armed conflict and violent environments, representing a double public health problem. The study aims to estimate the prevalence of different types of school violence perpetrated and experienced by school adolescents in a community with a history of exposure to armed conflict. Two thousand one hundred eighty-five school adolescents from a municipality in Colombia (males = 54.1%, 14-16 years = 38.6%) participated in the study. Nine educational institutions were included. A systematic random sampling was designed, with a proportional allocation of 35% within each school year from sixth to eleventh grade. The School Coexistence and Circumstances Affecting it-ECECA survey was applied. The prevalence and risks of bully and bullying were estimated. RRa were calculated with the 95% confidence interval adjusted for the other confounding variables. Analyses were constructed from generalized linear models, under the Poisson family and a logarithmic link function. We found a 9.3% of bullying victimization and a 3.5% prevalence of bully. A higher risk of bully was found among males, persons between 10 and 14 years of age, residents of rural or urban dispersed areas, residents of violent neighborhoods, alcohol consumers at school, and victims of aggression in childhood (RRa > 1.0, p-values <.05). The risk of victimization of bullying was higher in students younger than 15 years old, as residents of urban areas, having a history of childhood aggression, suffering abuse by a close person, and as alcohol users at school. This study provides evidence of risk factors for aggression and bullying that have implications for possible prevention measures in multiple social domains, including the individual, the family, and the school environment.


Assuntos
Conflitos Armados , Bullying , Humanos , Adolescente , Bullying/estatística & dados numéricos , Masculino , Feminino , Estudos Transversais , Fatores de Risco , Colômbia/epidemiologia , Criança , Vítimas de Crime/estatística & dados numéricos , Vítimas de Crime/psicologia , Instituições Acadêmicas , Prevalência , Estudantes/estatística & dados numéricos , Estudantes/psicologia , Comportamento do Adolescente/psicologia , Agressão
4.
Artigo em Inglês | MEDLINE | ID: mdl-38055376

RESUMO

One of the main challenges in the clinical management of dengue is the early identification of cases that could progress to severe forms of the disease. A biomarker that may enable this identification is the presence of genetic polymorphisms in genes associated with immune responses. The objective of this study was to perform a systematic review of the Latin American literature on these genes. An electronic literature search was carried out in PubMed, Scopus, Lilacs, and the Virtual Health Library, and reference lists of systematic reviews in the area. Case-control studies conducted in Latin American countries examining at least one form of genetic polymorphism related to immune responses against severe dengue were included. In total, 424 articles were identified and 26 were included in this systematic review. Of the 26 selected articles, 16 reported polymorphisms associated with the risk of developing severe dengue (Risk); Similarly, 16 articles reported polymorphisms associated with a decreased risk of severe dengue (Protective). The final analysis revealed that multiple polymorphisms in immune system genes were early markers of the progression of dengue in Latin Americans and found that polymorphisms of the TNF-alpha gene may have a critical role in dengue pathogenesis.


Assuntos
Dengue , Dengue Grave , Humanos , Dengue Grave/genética , América Latina , Dengue/genética , Revisões Sistemáticas como Assunto , Polimorfismo Genético/genética
5.
Rev. chil. obstet. ginecol. (En línea) ; Rev. chil. obstet. ginecol;88(6): 359-365, dic. 2023. tab
Artigo em Espanhol | LILACS | ID: biblio-1530034

RESUMO

Objetivo: Evaluar la prevalencia de fallo en la regulación de la fertilidad posparto y la asociación con otros factores en un municipio colombiano (2017). Método: Estudio observacional de corte transversal con 148 mujeres. Se aplicó un muestreo no aleatorio para incluir mujeres que hubieran tenido un parto en los últimos 5 años. Se calcularon la prevalencia y las razones de prevalencia. Se exploró la asociación con la prueba χ2 o la prueba exacta de Fisher bajo una significancia estadística de 0,05. Resultados: Se encontró una prevalencia de fallo de la regulación de la fertilidad posparto del 40,5%. La prevalencia se asoció con ejercer oficios del hogar, tener uno o dos hijos, no planificar o no acceder a métodos de planificación y haber tenido un embarazo con periodo intergenésico menor de 2 años (p < 0,05). Conclusiones: Es necesario implementar estrategias para identificar barreras de acceso a la planificación, impactando en el espaciamiento entre embarazos y el acceso a los servicios. Lo anterior para generar múltiples beneficios para la madre, su hijo/a, el sistema de salud y la sociedad.


Objective: To evaluate the prevalence of regulated postpartum fertility failure and possible associated factors in a Colombian municipality (2017). Method: Cross-sectional observational study of 148 women. A non-random sampling method was used to include women who had given birth to a child in the last five years. Prevalence and prevalence ratios were calculated. Associations were examined at 0.05 statistical significance using χ2 test or Fishers exact test. Results: The prevalence of postpartum fertility failure was found to be 40.5%. The prevalence was associated with household work, having one or two children, not planning, or not having access to planning methods, and having a pregnancy with an interval between pregnancies of less than 2 years (p < 0.05). Conclusions: It is necessary to implement strategies to identify barriers to access to planning, which have an impact on the spacing between pregnancies and access to services. This will have multiple benefits for mother, child, health system and society.


Assuntos
Humanos , Feminino , Planejamento Familiar , Prevalência , Estudos Transversais , Inquéritos e Questionários , Análise de Variância , Colômbia/epidemiologia , Anticoncepção
6.
PLoS One ; 18(11): e0294177, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38015897

RESUMO

BACKGROUND: Arterial hypertension is one of the most prevalent chronic, non-communicable diseases and the leading preventable risk factor for cardiovascular disease (CVD) and all-cause mortality worldwide. Although its primary causes and consequences are preventable, it often remains undiagnosed. Consequently, this study aims to determine the prevalence and factors associated with normotensive, diagnosed, and undiagnosed hypertension in adults. METHODS: A cross-sectional, population-based study was conducted in Sabaneta, Colombia, between 2021 and 2022, with 286 adults aged 18 and older. Stratified and systematic random sampling methods were employed. The World Health Organization STEP survey and the Perez Rojas test were utilized to assess behavioral risk factors and sedentary lifestyles. Body mass index, waist circumference, and arterial tension were measured using standardized instruments. The prevalence of hypertension was then estimated. Risk factors influencing normotensive, diagnosed, and undiagnosed hypertension were analyzed using multinomial regression. The outcome variable comprised three categories: normotensive (reference category), diagnosed hypertension, and undiagnosed hypertension. The multinomial regression coefficients were exponentiated and are presented as relative risk ratios (RRR) with 95% confidence intervals (CI). The model was adjusted for sex and sample weight per neighborhood. RESULTS: The study revealed a hypertension prevalence of 38.5% and an undiagnosed hypertension rate of 50.9%. Those with undiagnosed hypertension were predominantly adults over 60 years (RRR = 0.68; 95% CI: 0.53-0.86), individuals with an elementary school education (RRR = 1.75; 95% CI: 1.27-2.42), those physically active (RRR = 1.52; 95% CI: 1.22-1.89), without prior diagnoses of chronic comorbidities (RRR = 1.42; 95% CI: 1.12-1.82), and with obesity (RRR = 2.25; 95% CI: 1.63-3.11) or overweight conditions (RRR = 1.70; 95% CI: 1.334-2.15). CONCLUSIONS: Undiagnosed hypertension was significant among populations without risk conditions. There is an urgent need for community-based early detection and education strategies to mitigate this issue.


Assuntos
Hipertensão , Adulto , Humanos , Estudos Transversais , Colômbia/epidemiologia , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Fatores de Risco , Atenção Primária à Saúde , Prevalência
7.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1529452

RESUMO

ABSTRACT One of the main challenges in the clinical management of dengue is the early identification of cases that could progress to severe forms of the disease. A biomarker that may enable this identification is the presence of genetic polymorphisms in genes associated with immune responses. The objective of this study was to perform a systematic review of the Latin American literature on these genes. An electronic literature search was carried out in PubMed, Scopus, Lilacs, and the Virtual Health Library, and reference lists of systematic reviews in the area. Case-control studies conducted in Latin American countries examining at least one form of genetic polymorphism related to immune responses against severe dengue were included. In total, 424 articles were identified and 26 were included in this systematic review. Of the 26 selected articles, 16 reported polymorphisms associated with the risk of developing severe dengue (Risk); Similarly, 16 articles reported polymorphisms associated with a decreased risk of severe dengue (Protective). The final analysis revealed that multiple polymorphisms in immune system genes were early markers of the progression of dengue in Latin Americans and found that polymorphisms of the TNF-alpha gene may have a critical role in dengue pathogenesis.

8.
Adv Appl Bioinform Chem ; 14: 117-132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34447254

RESUMO

BACKGROUND: Uvaria scheffleri (Annonaceae), Clematis burgensis (Ranunculaceae), and Euphorbia schimperiana (Euphorbiaceae) are medicinal plants traditionally used to treat cough, tuberculosis, asthma, sore throat and skin infections. METHODS: Silica gel column chromatographic separation was used to isolate compounds. Crude extract and isolated compounds were evaluated for antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans via the broth dilution method. Docking studies were performed with E. coli DNA-Gyrase B and human DNA topoisomerase IIα by using AutoDock Vina. ADMET were predicted by SwissADME, PreADMET, and OSIRIS Property predictions. The optimized structures and molecular electrostatic potential surface of the isolated compounds were predicted by DFT analysis using B3LYP/6-31G basis levels. RESULTS: Silica gel column chromatographic separation afforded five compounds 1-5 of which N-methyl-2,3-bis(2-hydroxybenzyl)-1Н-indol (1) is reported herein for the first time, along with known C-benzylated dihydrochalcone uvaretin (2), bis(2-ethylheptyl) phthalate (3), lupeol (4) and suberosin derivative (5). Dichloromethane roots extract of U. scheffleri showed potent antibacterial activity against S. aureus (MIC = 6.25 µg/mL) compared to gentamicin (MIC=5 µg/mL). In silico, molecular docking analysis of compounds (1and 3-5) showed strong interaction with E. coli DNA gyrase B with a binding energy value ranging from -6.9 to -6.0 kcal/mol compared to ciprofloxacin -7.2 kcal/mol, whereas analysis against human topoisomerase IIα showed binding energy value ranging from -5.9 to -5.3 kcal/mol compared to vosaroxin (-6.2 kcal/mol). CONCLUSION: The results obtained suggest that N-methyl-2,3-bis(2-hydroxybenzyl)-1Н-indol (1) and coumarin (5) are potential topoisomerase II α inhibitors and might be used as anticancer agents. The ADMET studies showed the highest drug-likeness properties for studied compounds other than bis(2-ethylheptyl) phthalate (3). DFT calculations suggested that studied compounds showed the lowest gap energy and were chemically reactive, and isolated compounds may serve as potential drug candidates that corroborate with the traditional uses of studied plants.

9.
Chemistry ; 23(59): 14707-14711, 2017 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-28845883

RESUMO

Unlike their isocyano and isothiocyanato analogues, isocyanato esters remain almost unexplored as formal 1,3-dipoles in asymmetric catalytic reactions. The first asymmetric formal [3+2] cycloaddition involving isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with α,ß-unsaturated N-(o-anisidyl) imines in the presence of a Mg(OTf)2 -BOX complex to give highly substituted chiral pyrrolidinones featuring a conjugate exocyclic double bond with excellent yields and enantiomeric excesses up to 99 %. Several transformations of the resulting heterocycles, including the synthesis of a pyroglutamic acid derivative, have been carried out.


Assuntos
Ésteres/química , Iminas/química , Lactamas/química , Alcenos/química , Catálise , Complexos de Coordenação/química , Cristalografia por Raios X , Reação de Cicloadição , Isocianatos/química , Lactamas/síntese química , Magnésio/química , Malonatos/química , Conformação Molecular , Estereoisomerismo
10.
Org Biomol Chem ; 15(18): 3849-3853, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28406259

RESUMO

Copper triflate-BOX complexes catalyse the enantioselective conjugate addition of methyl malonate to ß-trifluoromethyl-α,ß-unsaturated imines to give the corresponding enamines bearing a trifluoromethylated stereogenic centre with good yields, and diastereo- and enantioselectivities. The usefulness of the method has been shown with the synthesis of optically active ß-trifluoromethyl δ-amino esters and optically active trifluoromethyl piperidones.

11.
Chemistry ; 19(44): 14861-6, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24105771

RESUMO

The asymmetric conjugate addition of malonate esters to α,ß-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 ŠMS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.

12.
Rev. colomb. gastroenterol ; 28(2): 134-145, jun. 2013. ilus
Artigo em Espanhol | LILACS | ID: lil-680526

RESUMO

A propósito del caso de un paciente de 7 meses de vida remitido desde Yopal a la ciudad de Bogotá, se revisa el tema de la linfagiectasia intestinal. Esta es una rara enfermedad que involucra los vasos linfáticos intestinales, y origina hipoproteinemia, edemas, ascitis y enteropatía perdedora de proteínas.


This is the case report of a 7 month old child from Yopal with intestinal lymphangiectasia who was sent to Bogota. We also review the issue of intestinal lymphangiectasia, a rare disease involving intestinal lymphatic vessels which caused hypoproteinemia, edema, ascites and protein-losing enteropathy.


Assuntos
Humanos , Masculino , Recém-Nascido , Ascite , Hipoproteinemia , Linfangiectasia Intestinal , Enteropatias Perdedoras de Proteínas
13.
J Org Chem ; 77(23): 10545-56, 2012 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23126442

RESUMO

Experimental and theoretical studies on the structure of several complexes based on (R)-3,3'-Br(2)-BINOL ligand and group (IV) metals used as catalysts in an enantioselective Friedel-Crafts alkylation of indoles with α,ß-unsaturated ketones have been carried out. NMR spectroscopic studies of these catalysts have been performed, which suggested that at room temperature the catalysts would form a monomeric structure in the case of Ti(IV) and a dimeric structure in the cases of Zr(IV) and Hf(IV). Density functional theory (DFT) calculations clearly corroborate the conclusions of these experimental spectroscopic studies. The dimeric structure with a doubly bridged motif [Zr(IV)(2)(µ-(R)-3,3'-Br(2)-BINOL)(2)] where each binaphthol ligand acts as bridge between the metal centers (Novak's model) is more stable than the dimeric structure with a doubly bridged motif [Zr(IV)(2)(µ-O(t)Bu)(2)] where the tert-butoxide groups act as bridging ligands (Kobayashi's model). The scope of the Friedel-Crafts alkylation with regard to the indole structure has been studied. Finally a plausible mechanism for the Friedel-Crafts reaction and a stereomodel for the mode of action of the catalyst that explain the observed stereochemistry of the reaction products have been proposed.


Assuntos
Indóis/química , Cetonas/química , Naftóis/química , Zircônio/química , Alquilação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Estereoisomerismo
14.
Chemistry ; 18(41): 12966-9, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-22936365

RESUMO

Zinc for conjugate alkynylation: The enantioselective conjugate addition of terminal alkynes to 2-arylidene-1,3-diketones in the presence of diethylzinc and a catalytic amount of (R)-VANOL has been developed. The reaction can be applied to different aromatic and heteroaromatic alkynes and enones, giving the expected products in good yield and with enantiomeric excesses up to 91%. The products can be enantiomerically enriched up to 99% ee by crystallization (see scheme).

15.
Org Biomol Chem ; 7(20): 4301-8, 2009 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-19795072

RESUMO

A mandelamide ligand, derived from (S)-mandelic acid and (S)-phenylethanamine, catalyzes the addition of aryl-, alkyl- and silyl-alkynylzinc reagents to aromatic and heteroaromatic aldehydes with good yields and good to high enantioselectivities.

17.
J Org Chem ; 71(13): 4929-36, 2006 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-16776523

RESUMO

Several 4,5-epoxy-9-trimethylsilyl-eudesmanes and 15-nor-eudesmanes, having different relative stereochemistry and substitution at the oxirane ring, have been prepared starting from (-)-carvone and subjected to acid-promoted rearrangement. The presence of the silicon at C9 favors two different main reaction pathways involving C14-methyl or C1-methylene migration through the stabilization of a C10 carbocation intermediate. Selective 1,2-migration of the bridgehead methyl group takes place with trisubstituted beta-epoxide and tetrasubstituted alpha-epoxide, yielding 4-hydroxy-eremophilane and 15-nor-eremophilane compounds, while the trisubstituted alpha-epoxide suffers successive rearrangements to give a 1-hydroxy-15-nor-eremophilane through a pathway involving the initial migration of the C1 methylene. The synthetic utility of these rearrangements is shown by the synthesis of natural (-)-aristolochene.


Assuntos
Naftalenos/química , Sesquiterpenos/síntese química , Conformação Molecular , Naftalenos/síntese química , Sesquiterpenos/química , Estereoisomerismo
18.
J Org Chem ; 69(21): 7294-302, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15471483

RESUMO

The synthesis of the spirovetivane sesquiterpenes (+)-anhydro-beta-rotunol and all the diastereomers of 6,11-spirovetivadiene in enantiomerically pure form has been achieved starting from santonin. The key step is the silicon-guided acid-promoted rearrangement of a 1-trimethylsilyl-4,5-epoxyeudesmane prepared from santonin in several steps involving lactone reductive opening, conjugate addition of TMSLi-CuCN, deoxygenation of a carbonyl group, and epoxidation. Rearrangement of the epoxide gave a spiro[4,5]decanediol which was used as a synthetic intermediate. From this compound, (+)-anhydro-beta-rotunol was prepared after elimination of the primary hydroxyl group in the side chain, followed by allylic oxidation at C8 and elimination of the tertiary hydroxyl group in the cyclohexane ring. On the other hand, elimination of the hydroxyl group in the side chain and reduction of the hydroxyl in the cyclohexane ring gave (-)-premnaspirodiene and (-)-hinesene. The synthesis of the rest of the diastereomers for these compounds required formal inversion of the C5 spiro carbon. The synthesis of these compounds showed that the structure of (-)-agarospirene isolated from Scapania sp. was erroneously assigned, and it has been corrected to be identical to that of (-)-hinesene.


Assuntos
Santonina/química , Sesquiterpenos/síntese química , Compostos de Espiro/síntese química , Conformação Molecular , Estereoisomerismo
19.
J Org Chem ; 69(20): 6821-9, 2004 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-15387607

RESUMO

An easy access to substituted (R)-3-hydroxy-3-phenyloxindoles, (R)-benzylic acids, and benzophenones is described. The reaction of the lithium enolate of the (2S,5S)-cis-1,3-dioxolan-4-one derived from optically active (S)-mandelic acid and pivalaldehyde with several o- and p-halonitrobenzenes proceeds readily to give the corresponding arylation products in good yields and diastereoselectivities. The reduction of the nitro group with Zn/HCl/EtOH in the o-nitro arylation products with concomitant intramolecular aminolysis of the dioxolanone moiety leads directly to enantiomerically pure (R)-3-hydroxy-3-phenyloxindoles. On the other hand the basic hydrolysis of the dioxolanone moiety in all the arylation products (ortho and para) leads to enantiomerically pure substituted (R)-benzylic acids. The oxidative decarboxylation of these latter with oxygen as terminal oxidant in the presence of pivalaldehyde and the Co(III)-Me2opba complex as catalyst gives substituted nitrobenzophenones.

20.
J Nat Prod ; 65(11): 1703-6, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12444708

RESUMO

Starting from 2 and 3, obtained from santonin (1), we have synthesized natural guaianolides 4-7. Chemoselective epoxidation of 2 gave (+)-11betaH,13-dihydroestafiatin (4), and epoxidation of 3 followed by regioselective elimination of the hydroxyl group afforded (+)-11betaH,13-dihydroludartin (5). Sharpless' mild regioselective ring-opening of 4 and 5 followed by hydrogenolysis yielded (-)-compressanolide (6) and (-)-11betaH,13-dihydromicheliolide (7), respectively.


Assuntos
Lactonas/síntese química , Santonina/química , Santonina/síntese química , Catálise , Ciclização , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Santonina/análogos & derivados , Estereoisomerismo
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