PURPOSE: To obtain an optically active 2-substituted-2-cyclopentenone useful as a carcinostatic agent or a bone formation promoter.
CONSTITUTION: A compound of formula I (R1 is 1-10C aliphatic hydrocarbon, 4-10C alicyclic hydrocarbon, etc.; R2 is as shown for R1; R3 is 1-10C aliphatic hydrocarbon, 4-10C alicyclic hydrocarbon, etc.; R4 is H, 1-4C alkyl, etc., or group forms acetal bond from O linked to R4, R5 is 1-10C aliphatic hydrocarbon or 4-10C alicyclic hydrocarbon: A is H, OH, etc.; B is H or A and B are bonded to form single direct bond; n is 0-2; * is asymmetric hydrocarbon having induced optical activity) such as a compound of formula II. The compound of formula I, for example, is obtained by epoxidizing an optically active 2- cyclopentenone of formula III to give a compound of formula IV, reacting this compound with a thiol of the formula R-SH in the presence of a basic compound to give a compound of formula V, then optionally carrying out oxidation reaction, deprotecting reaction of OH-protecting group, OH-protecting reaction, etc.
TAKEUCHI TAKAHIRO
KATO YOSHINORI
HASATO ATSUO
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