Kan K. Eng

Highly diastereoselective reaction of a chiral, non-racemic amide enolate with (S)-glycidyl tosylate. Synthesis of the orally active HIV-1 protease inhibitor L-735,524

Abstract Reaction of chiral amide enolate Li-1 with (S)-glycidyl tosylate 11 affords the epoxide 3 in 72% yield with high diastereoselectivity. Epoxide 3 is converted to the orally-active HIV-1 protease inhibitor L-735,524 in 71% isolated yield.

Diastereoselective syn-epoxidation of 2-alkyl-4-enamides to epoxyamides: Synthesis of the Merck HIV-1 protease inhibitor epoxide intermediate

Abstract Reaction of 2-alkyl-4-enamides 2, 9–15 with NIS and aqueous sodium bicarbonate results in the diastereoselective formation of the corresponding iodohydrins 3, 16–22 with essentially no iodolactone by-product. This methodology has been successfully employed for the synthesis of the epoxide intermediate 4 of the orally active Merck HIV-1 protease inhibitor L-735,524.

An efficient asymmetric synthesis of (R)-3-amino-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one

Abstract Two approaches for the asymmetric preparation of (−)- or (+)- α-aminobenzlactam 1 are described. One route is based on the asymmetric hydrogenation of enamide 5 and the other on the racemization/resolution of (±)- 1 .

Cyclic imidate salts in acyclic stereochemistry: Diastereoselective syn-epoxidation of 2-alkyl-4-enamides to epoxyamides

Abstract Reaction of 2-alkyl-4-enamides with 1 + and aqueous sodium bicarbonate results in the diastereoselective formation of the corresponding iodohydrins with essentially no iodolactone by-product. The reaction appears to proceed through a cyclic imidate type intermediate. This methodology has been successfully employed for the synthesis of the epoxide intermediate of the orally active HIV-1 protease inhibitor MK-639 (indinavir sulfate).