GAS-CHROMATOGRAPHIC ANALYSIS OF DIASTEREOMERS AND ENANTIOMERS OF BETA,GAMMA-UNSATURATED ESTERS AND VARIOUS ANALOGS OF BUTENOLIDES INCLUDINGMINT AND ISOMINT LACTONE AND COMPARISON WITH THE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ANALYSIS OF THEIR DIASTEREOMERS

Butenolide is an alpha,beta-unsaturated lactone. The butenolide moiety is present in numerous biologically active natural products, especial ly insect sex hormones. A method was developed for the synthesis of bu tenolides from beta,gamma-unsaturated esters. Separation of diastereom ers and enantiomers of these esters and butenolides including mint and isomint lactone and heritionin by GC is reported. The order of elutio n of isomers of mint and isomint lactone was identified as RR, SS, SR and RS on a Chirasil-Val-D column. This was also confirmed by injectin g these samples on to a column with an L-configuration. The separation of diastereomers by HPLC was also tried and the results were compared with those obtained by GC.