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1.
Org Lett ; 24(44): 8233-8238, 2022 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-36326444

RESUMEN

Herein, we report a CuH-catalyzed asymmetric desymmetrization of prochiral cyclopentane-1,3-diones to access cyclic 3-hydroxy ketones having an all-carbon quaternary center with high diastereoselectivity via hydrosilylation using PMHS as an inexpensive hydride source. This reaction displays high functional group tolerance including reducible alkyne, alkene, and ester groups with a broad substrate scope. The importance of chiral cyclic 3-hydroxy ketone building blocks was also demonstrated through the synthesis of (-)-estrone, the toxicodenane E core, and fused indoles.


Asunto(s)
Alquenos , Cetonas , Estereoisomerismo , Catálisis , Indoles
2.
Chem Commun (Camb) ; 57(45): 5574-5577, 2021 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-33969843

RESUMEN

One-pot sequential p-hydroxybenzylation/oxidative dearomatization/spiroannulation has been designed for the efficient construction of tetrahydrofuran containing spiro-cyclohexadienones. This reaction proceeds through the p-hydroxybenzylation of 1,3-diketones with p-hydroxybenzyl alcohol via quinone methide formation followed by oxidative dearomatization/spiroannulation with suitable alcohols. The Friedel-Crafts alkylation of spiro[4.5]cyclohexadienones with indoles provided a broad array of highly diastereoselective C-3 alkylated spirocycles and cyclohepta[b]indoles depending upon the ring size of the fused cyclic ketones.

3.
Chem Sci ; 12(4): 1544-1550, 2020 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-34163917

RESUMEN

A Rh(i)-catalyzed highly stereoselective desymmetrization of 2-alkynylbenzaldehyde-tethered cyclohexadienones triggered by intramolecular Huisgen-type [3 + 2] cycloaddition has been developed. This method enables convergent construction of complex epoxy-bridged polycyclic ring systems with five contiguous stereocenters with excellent exo-selectivity and broad substrate scope. The highly atom-economical process involves 6-endo-dig cyclization of carbonyl oxygen onto an activated alkyne resulting in a highly reactive metal-benzopyrylium intermediate, which readily undergoes intramolecular [3 + 2] annulation/hydration. Asymmetric induction is also achieved for the first time in Rh(i)-catalyzed 1,3-dipolar cycloaddition using an easily accessible chiral diene as the ligand.

4.
Int J Trichology ; 11(6): 227-231, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32030055

RESUMEN

BACKGROUND: Research on the association between androgenetic alopecia (AGA) and coronary artery disease (CAD) in women, with a focus on the evaluation of their angiographic association in the form of the severity of disease, has been lacking. AIM: The study aimed to evaluate the relation between CAD and AGA in women and to study their severity. METHODS: This study, carried out with 438 women within 55 years of age and admitted for coronary angiography, had the case group (participants with CAD; n = 219) and control group (those without CAD; n = 219). The clinical and paraclinical data were collected after clinical history, physical examination, and review of the patients' records (family, past, and personal history of the participants). The coronary risk profiles such as diabetes mellitus, blood pressure, and serum cholesterol level were also noted, and the diagnosis of AGA was performed, and participants were grouped using the Ludwig's baldness grading system. Statistical analysis was performed by studying association between the variable using the Chi-square test (R i386.3.5.1 software). RESULTS: In the study group, 74 (33.79%) participants were treadmill test positive, 55 (25.11%) had unstable angina, 40 (18.26%) had ST-segment elevation myocardial infarction (STEMI), and 50 (22.83%) had non-ST-STEMI (NSTEMI). In the case group, Grade II female AGA was evidenced in 38 (43.18%) participants, whereas Grade III was present in 30 (34.09%) participants. Further on, 27 patients with triple vessel disease had Grade III female AGA. Whereas, in the control group, Grade I female AGA was evidenced in 23 (65.71%) participants. CONCLUSION: The hypothesis that female pattern baldness is a marker for increased risk of CAD events has been studied and established as part of the present study. Further, extensive studies on the effect of other variables with a larger sample size need to be conducted.

5.
Indian Dermatol Online J ; 6(3): 189-92, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26009714

RESUMEN

Rhinocerebral mucormycosis is the most common form of mucormycosis occurring commonly in patients of diabetic ketoacidosis. Fungi of the order Mucorales belong to six families, among whom Rhizopus is the most common, while Mucor is a rare cause. We report a 45-year-old female with uncontrolled diabetes mellitus diagnosed to have rhinocerebrocutaneous mucormycosis caused by Mucor species. The diagnosis was confirmed on histology and culture. A high-index of suspicion is required for early diagnosis and timely initiation of therapy to optimize the outcome. Our patient succumbed to her infection.

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