Contact Sex Pheromone Activity of Synthetic Gomadalactones in Male White-Spotted Longhorn Beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae).

The elytra of females of the white-spotted longhorn beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae), are coated with a contact sex pheromone, which was previously shown to be composed of at least three chemical groups. Individually, the chemical groups had little pheromonal activity, but a blend of all three exhibited activity equal to that of the crude female extract. Two groups are female-specific aliphatic hydrocarbons and ketones, which were previously synthesized and confirmed to elicit mating behavior. The third group consists of three lactones, gomadalactones A, B, and C, whose chemical structures were previously identified. These have now been synthesized, and the contact sex pheromone activities of synthetic gomadalactones A, B, and C, and the diastereomer of gomadalactone C, were tested in bioassays in this study. When tested in combination with synthetic hydrocarbons and ketones at the same doses as found in female elytra extract, the individual gomadalactones and a blend showed potent pheromonal activity equivalent to that of the crude extract of the elytra of female beetles. This completes the identification of the essential components of the contact sex pheromone of A. malasiaca. Redundancy of components in the hydrocarbon and ketone groups required to elicit mating behavior was observed previously, and this was also true for the gomadalactones.

Recent Advances of Total Syntheses of Diterpenoids Starting from Carvone.

This review focuses on total syntheses of diterpenoids starting from carvone (1) since 2006 in the alphabetical order of compound names.

An active, general, and long-lived palladium catalyst for cross-couplings of deactivated (hetero)aryl chlorides and bromides with arylboronic acids.

An active, general, and long-lived palladium catalyst for Suzuki-Miyaura reactions of aryl and heteroaryl chlorides deactivated by steric hindrance, electron richness, and coordinating functional groups is reported. In reactions of arylbromide bearing two o-tert-butyl substituents, C(sp(3))-H arylation of the tert-butyl group, rather than the Suzuki-Miyaura reaction, proceeded in excellent yield. The key to the success of the reactions was the development of biphenylene-substituted dicyclohexylruthenocenylphosphine (CyR-Phos) as a supporting ligand.

Second generation synthesis of the neo-clerodane diterpenoid methyl barbascoate.

The second generation total synthesis of the neo-clerodane diterpenoid, methyl barbascoate, was accomplished in seven or nine linear steps via double enol triflation and subsequent palladium catalyzed double carbonylation, followed by regioselective samarium diiodide mediated conjugate reduction.

Carvone as a versatile chiral building block for total syntheses of heterocyclic sesquiterpenoids.

This review article is focused on the total syntheses of heterocyclic sesquiterpenoids starting from carvone since 1996.

Revisit to (Z)-civetone synthesis.

The synthesis of (Z)-civetone (1) is described starting from oleic acid (5) via a series of reactions, intermolecular olefin self-metathesis, bromination/dehydrobromination into acetylene, semi-hydrogenation and intramolecular Dieckmann macrocyclization.

Total synthesis of the bicyclic marine sesquiterpenoid drechslerine B.

The total synthesis of the recently isolated bicyclic sesquiterpenoid drechslerine B (2), isolated from the algicolous fungus Drechslera dematioidearare in the marine red alga Liagora viscida, has been achieved, starting from (S)-carvone (8), via an intramolecular aldol reaction and palladium-catalyzed carbon monoxide insertion as key reactions.

Highly enantioselective Pd-catalyzed allylic alkylation of indoles using Sulfur-MOP ligand.

The preparation of various (R)-Sulfur-MOP ligands with aryl and alkyl substituents on sulfur, and the application of these ligands to Pd-catalyzed asymmetric allylic alkylation of indoles is reported. The sulfur substituent served as an effective stereocontrol element, and in the case of the 2-i-PrPh substituent on sulfur, the allylation products from an array of simple and substituted indoles were obtained with high enantioselectivity (up to 95% ee).

Biphenylene-substituted ruthenocenylphosphine for Suzuki-Miyaura coupling of sterically hindered aryl bromides.

A highly general, active, and stable catalytic system was realized in the palladium-catalyzed Suzuki-Miyaura reactions of sterically hindered aryl bromides with arylboronic acids using biphenylene-substituted di-tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand.

Biphenylene-substituted ruthenocenylphosphine for Suzuki-Miyaura coupling of aryl chlorides.

High activity in the palladium-catalyzed Suzuki-Miyaura reactions of aryl chlorides with arylboronic acids was furnished using biphenylene-substituted di- tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand. Substrate combinations even for the construction of highly hindered tetra- ortho-substituted biaryls can be achieved in good to excellent yields with low catalyst loadings in short reaction times.

Total synthesis of the hallucinogenic neoclerodane diterpenoid salvinorin A.

Total synthesis of salvinorin A (1), a neoclerodane diterpenoid having the most potent hallucinogenic activity and a selective kappa-opioid agonist, was completed in 20 steps starting from enantiomerically pure hydroxy-Wieland-Miescher ketone 5.

Supported ionic liquid catalyst (Pd-SILC) for highly efficient and recyclable Suzuki-Miyaura reaction.

Highly efficient Suzuki-Miyaura coupling of aryl halides with arylboronic acid was realized in 50% aqueous ethanol at room temperature employing Pd(OAc)(2) immobilized in diethylaminopropylated (NDEAP) alumina pores with the aid of [bmim]PF(6), which enabled recycle use up to five times in 95% average yield and turnover number of two million.

Synthetic transformation of ptychantin into forskolin and 1,9-dideoxyforskolin.

Forskolin (1), a highly oxygenated labdane diterpenoid and an activator of adenylate cyclase, has been synthesized in 12 steps and 12% overall yield from ptychantin A (4), which has been isolated from liverwort Ptychanthus striatus in good yield. The 1alpha-hydroxy group was furnished by stereoselective reduction of the corresponding carbonyl group by sodium in t-BuOH. The 9alpha-hydroxy group was introduced stereoselectively by epoxidation of delta(9.11)-enolether. 1,9-Dideoxyforskolin (2), an inhibitor of glucose transporter, has been synthesized in 8 steps and 37% overall yield. The hydroxy group at C-1 was removed by solid-state thicarbonylimidazolation and subsequent radical cleavage.

Knoevenagel reaction in water catalyzed by amine supported on silica gel.

An environmentally benign and sustainable Knoevenagel reaction of aldehyde with ethyl cyanoacetate has been achieved at ambient temperature in water employing 3-aminopropylated silica gel (NAP) as a catalyst. Wide applicability of the reaction is illustrated by the results that not only arylaldehydes of both electronic characters but also aliphatic aldehydes afforded the products. The reaction condition was so mild that aldehydes having acid- or base-sensitive substituents provided substituted alpha-cyano-alpha, beta-unsaturated esters. The catalyst has been efficiently recycled more than five times without any pre-treatment. Catalyst loading was successfully reduced to 0.0029 mmol% (TON = up to 9,226). This protocol was also applicable to the Knoevenagel reaction of malononitrile in good yields in water.

Enantiomerically pure 2-bromo-2'-diphenylphosphinyl-1,1'- binaphthyl as a monophosphorus template for electrophilic functionalization in chiral MOP-type ligand synthesis.

[reaction: see text] Pd-catalyzed monophosphinylation of (R)-2-bromo-2'-iodo-1,1'-binaphthyl with Ph(2)P(O)H afforded (R)-2-bromo-2'-diphenylphosphinyl-1,1'-binaphthyl in good yield with excellent chemoselectivity and no observable racemization. Subsequent lithiation in the presence of excess thiosulfonate furnished an enantiomerically pure sulfenylation product, which was reduced to afford a chiral S-MOP ligand.

Sustainable Mizoroki-Heck reaction in water: remarkably high activity of Pd(OAc)2 immobilized on reversed phase silica gel with the aid of an ionic liquid.

Palladium acetate immobilized on reversed phase amorphous silica gel with the aid of an ionic liquid, [bmim]PF6, was highly efficient in the promotion of the Mizoroki-Heck reaction in pure water without a ligand up to the sixth re-use, in 95% average yield with TON and TOF 1,600,000 and 71,000 (h(-1)), respectively.

The first total synthesis of (-)-methyl barbascoate.

[reaction: see text] The neo-trans-clerodane natural product, (-)-methyl barbascoate 1, has been synthesized for the first time starting from the known ketone 6 derived from (R)-(-)-Wieland-Miescher ketone analogue 5.

Immobilization of Pd(OAc)(2) in ionic liquid on silica: application to sustainable Mizoroki-Heck reaction.

[reaction: see text] Palladium acetate was supported on amorphous silica with the aid of an ionic liquid, [bmim]PF(6). The immobilized catalyst was highly efficient in promoting the Mizoroki-Heck reaction without a ligand in n-dodecane for at least six reuses, in 89 approximately 98% yields. The TON and TOF reached 68 400 and 8000, respectively.