(4R,5R)-3-Acetylamino-4,5-dimethyl-(Z)-oct-2-enoic Acid Ethyl Ester → (3R,4R,5R)-3-Acetylamino-4,5-dimethyl-octanoic Acid Ethyl Ester

Participants

Reaction Steps

Ten mL ampoules were each charged with 20 mg of (4R,5R)-3-acetylamino-4,5-dimethyl-(Z)-oct-2-enoic acid ethyl ester (substrate), 2 mL of MeOH, and approximately 10 mg of catalyst. The ampoules were placed in a multi-reactor, purged with hydrogen, then pressurized to 20 psig with hydrogen and shaken at room temperature for 18 hours. For each ampoule following reaction, the solids were removed by filtration and the filtrate was analyzed by chiral GC (CHIRASIL-DEX CB, 140° C. isothermal). The table below provides conversion and ratio of (3R,4R,5R)-3-acetylamino-4,5-dimethyl-octanoic acid ethyl ester (desired diastereoisomer) to (3S,4R,5R)-3-acetylamino-4,5-dimethyl-octanoic acid ethyl ester (undesired diastereoisomer) for various hydrogenation catalysts.

Provenance & Evidence