Stereoselective synthesis of (−)-PF1163A via Prins cyclization

A highly stereoselective and convergent total synthesis of PF1163 A is described while proving the versatility of Prins cyclization in natural product synthesis. The Prins cyclization, Yamaguchi esterification, and ring-closing metathesis reactions are the key steps utilized in the synthesis of macrolactone

Stereoselective synthesis of 10,14- dimethyloctadec-1-ene, 5,9-dimethyloctadecane, and 5,9- dimethylheptadecane, the sex pheromones of female apple leafminer

The stereoselective synthesis of (10R,14R)-10,14-dimethyloctadec-1-ene (1), (5R,9R)-5,9-dimethyloctadecane (2), and (5R,9R)-5,9-dimethylheptadecane (3) the sex pheromone components of female apple leafminer was accomplished by reductive elimination tosyl and isonitrile groups of dialkylated tosylmethyl isonitrile. The key steps involved were dialkylation of TosMIC with 1-iodo 2-methyl alkanes, which were derived from Evan's alkylation of chiral auxiliary and subsequent reduction

Modular total synthesis of lamellarin G trimethyl ether

A modular synthesis of the lamellarin G trimethyl ether has been developed based on the application of several reaction -sequences which include Friedel-Crafts acylation, esterification, haloarylation, and oxidative cyclization. The formation of pyrrolo [2,1-a]isoquinoline core, the key step for the successful completion of lamellarin G trimethyl ether synthesis, is comfortably accomplished through the haloarylation of 3-bromo-4-(3,4-dimethoxy-benzoyl)-6,7-dimethoxy-chroman-2-one which has resulted in exclusive endo product

[Bmim]PF<SUB>6</SUB>/RuCl<SUB>3</SUB>·xH<SUB>2</SUB>O: a novel and recyclable catalytic system for the oxidative coupling of β-naphthols

2-Naphthols readily undergo oxidative coupling in the presence of RuCl<SUB>3</SUB>·xH<SUB>2</SUB>O in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF<SUB>6</SUB>) ionic liquid under aerobic conditions to afford binaphthols in excellent yields with high selectivity. The β-naphthols show enhanced reactivity in ionic liquids, thereby reducing reaction times and improving the yields significantly. The recovered ionic liquid containing ruthenium catalyst can be reused in three to four successive runs with a gradual decrease in activity

Bismuth (III) triflate catalyzed condensation of isatin with indoles and pyrroles: a facile synthesis of 3,3-diindolyl-and 3,3-dipyrrolyl oxindoles

Indoles and pyrroles undergo a rapid condensation with isatin in the presence of 2 mol&#x0025; of Bi(OTf)<SUB>3</SUB>, under mild reaction conditions, to afford the corresponding 3,3-di(3-indolyl)- and 3,3-di(2-pyrroryl)oxindoles in excellent yields and high regioselectivity. This method is ideal for the direct introduction of indoles and pyrroles onto an isatin moiety at the 3-position

Utility of semicarbazones as ligands in newly made palladium complex for facile Suzuki homocoupling reaction of alkyl and aryl boronic acids

An air stable catalytic system [Pd (HSal4NH2) Cl] catalyst was found to be highly effective in the Suzuki homocoupling of alkyl and aryl boronic acids resulting in bialkyls and biaryls

Stereoselective total synthesis of (-)-colletol by Prins cyclisation

A simple and efficient asymmetric total synthesis of the bis-macrolactone (-)-colletol was accomplished, proving the versatility of the Prins cyclisation in natural product synthesis. The synthesis mainly relies upon reductive opening of a pyran ring, Mitsunobu inversion, the Wittig reaction, and Yamaguchi macrolactonisation as the key steps

Daucus carota and baker's yeast mediated bio-reduction of prochiral ketones

Stereoselective reduction of prochiral ketones to the corresponding alcohols using biocatalysts has attracted much attention, from the viewpoint of green chemistry. Asymmetric reduction of indanone, tetralone and hydroxyl trimonoterpene ketones to the corresponding enantiomerically pure (S)-alcohols, using Daucus carota plant homogenate and fermented baker's yeast cells, is described. The present study illustrates the broad substrate selectivity of the dehydrogenase enzymes present in the D. carota in the synthesis of a wide range of chiral secondary alcohols of biological importance