Kavirayani R. Prasad

Stereoselective total synthesis of (+)-cardiobutanolide.

Stereoselective synthesis of styryllactone (+)-cardiobutanolide was accomplished in good overall yield from d-(-)-tartaric acid. Key features of the synthesis include the elaboration of a gamma-hydroxy butyramide obtained from the dimethylamide of tartaric acid, involving a combination of the addition of 1,3-dithian-2-yllithium and stereoselective reduction.

Formal Total Synthesis of Palmerolide A

A formal total synthesis of the 20-membered marine macrolide, palmerolide A from chiral pool tartaric acid is described. Elaboration of a γ-hydroxy amide, which is derived from the desymmetrization of tartaric acid amide, and Boord olefination are the pivotal reactions employed for the synthesis of the chiral building blocks, and Stille coupling and ring-closing metathesis (RCM) are used to assemble the macrolactone.

Total synthesis and determination of the absolute configuration of 5,6-dihydro-α-pyrone natural product synargentolide B.

Enantiospecific total synthesis and determination of the absolute stereochemistry of the α-pyrone-containing natural product synargentolide B were accomplished. The absolute stereochemistry of the natural product was established by synthesizing the possible diastereomers and comparison of the data with those reported for the natural product. During the process, total synthesis of the putative structure of related natural product 6R-[1S,2R,5R,6S-(tetraacetyloxy)-3E-heptenyl]-5,6-dihydro-2H-pyran-2-one was also accomplished and confirmed by X-ray crystal structure analysis. Wittig-Horner reaction of a chiral phosphonate derived from (S)-lactic acid and ring-closing metathesis were the key reactions during the course of the total synthesis.

Enantiospecific Total Synthesis of (−)‐Bengamide E

Total synthesis of the polyhydroxy caprolactam amide natural product, bengamide E, is accomplished starting from tartaric acid. Key reactions in the synthesis include desymmetrization of the bis(dimethylamide) unit of tartaric acid, Zn(BH(4))(2)-mediated anti-selective reduction, and a Horner-Wadsworth-Emmons olefination.

RCM-based approach to (±)-cuparene

Abstract An efficient approach to the aromatic sesquiterpene cuparene has been described starting from the readily available β‐ionone and employing a combination of epoxide rearrangement‐based ring‐contraction and ring‐closing metathesis reactions as key steps.

Asymmetric Synthesis Using Sulfinimines (N-Sulfinyl Imines)

Abstract Sulfinimine-derived polyfunctionalized chiral building blocks, often prepared in one pot, provide efficient access, with a minimum of chemical manipulation, to enantiopure, multifunctional amine derivatives including piperidines and pyrrolidines.

Oxazaborolidine catalysed enantioselective reduction of 2-acyl thiophenes and 2-acyl furans

Abstract 2-Thienyl and 2-furyl carbinols are prepared in good enantiomeric excess (up to 93% ee) through oxazaborolidine catalysed reduction of the corresponding ketones.