PURPOSE: To obtain easily the titled compound having excellent carcinostatic action from a high-purity optical active α-hydroxyketone compound which is obtained by carrying out optical resolution using an optical active α-glycol having a symmetric structure as a resolving agent.
CONSTITUTION: A racemic modification of an α-hydroxyketone shown by the formula I is treated with an optical active substance of an α-glycol shown by the formula II (R is p-chlorobenzyloxymethyl) to give a mixture of diastereomeric acetal derivative shown by the formula III-A and formula III-B (two Rs are in trans-position to each other), which are separated by selective crystallization, deacetalized, to give an optical active substance shown by the formula IV or formula V. The compound shown by the formula IV is acetalized, brominated, hydrolyzed to give a compound shown by the formula VI, which is further isomerized to give the desired compound shown by the formula VII. An unnecessary enantiomer prepared in the course of the optical resolution is usable repeatedly, and the recovery of the resolving agent can be carried out easily by a simple operation.
TAMOTO KATSUMI
SUGIMORI MASAMICHI