Process for producing optical active 4-hydroxy-2-cyclopentenone

A process for producing optically active 4-hydroxy-2-cyclopentenone (1) which comprises:

• reacting 4-hydroxy-2-cyclopentenone represented by the formula:
• ##STR11## with an optically active propargyl alcohol derivative represented by the general formula:
• ##STR12## wherein R and R' each independently represent a halogenated phenyl group, an alkylphenyl group, or an alkyl group which may be substituted by one or more halogen atom(s), and * indicates an asymmetric carbon atom, to form an optically active complex (3) consisting essentially of optically active 4-hydroxy-2-cyclopentenone represented by the formula:
• ##STR13## wherein * indicates an asymmetric carbon atom, and the optically active propargyl alcohol derivative (2), wherein the reaction is conducted in the presence of a solvent and at a temperature in a range of from -20.degree. C. to up to the boiling point of the solvent;
• and then decomposing the complex (3).

An optically active complex (3) consisting essentially of optically active 4-hydroxy-2-cyclopentenone represented by the formula (1):

• ##STR14## wherein * indicates an asymmetric carbon atom, and an optically active propargyl alcohol derivative (2) which is selected from the group consisting of (+) or (-)-1,4-bis(1-phenyl-1-(o-chlorophenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(o-bromophenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(o-fluorophenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(p-chlorophenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4bis(1-phenyl-1-(o-methylphenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(o-ethylphenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(p-methylphenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(p-propylphenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-(2-chloroethyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4bis(1-phenyl-1-(4-chlorobutyl)-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-propyl-1-hydroxypropynyl) benzene, (+) or (-)-1,4-bis(1-phenyl-1-methyl-1-hydroxypropynyl) benzene, (+) or (-)-(1-phenyl-1-(o-chlorophenyl)-1-hydroxypropynyl)-4-(1-phenyl-1-(o-bromo phenyl)-1-hydroxypropynyl) benzene, (+) or (-)-1-(1phenyl-1-(o-chlorophenyl)-1-hydroxypropynyl)-4-(1phenyl-1-(o-methy lphenyl)-1-hydroxypropynyl) benzene, and (+) or (-)-1-(1-phenyl-1-(o-bromophenyl)-1-hydroxypropynyl)-4-(1-phenyl-1-(o-ethy lphenyl)-1-hydroxypropynyl) benzene.