Abstract
Such (+)- and (-)-cw-cycloheximide isomers as isocycloheximide (la, lb), a-epiisocycloheximide (2a, 2b) and neocycloheximide (3a, 3b) were synthesized by aldol condensation of (-)-(2R, 4R)- and (+)-(2S, 4S)-cis-2, 4-dimethyl-l-cyclohexanone (5a, 5b), obtained by microbial resolution, with 4-(2-oxoethyl)-2, 6-piperidinedione (7). The absolute configuration of the ( - )-cisketone 5a was confirmed by chemical correlation with natural (2S, 4S, 6S, αR-cycloheximide (4). The newly synthesized isomer, (-)-α-epiisocycloheximide (2b), showed strong antimicrobial activity against S. cerevisiae and P. oryzae close to that of natural cycloheximide (4).
