METHOD FOR PRODUCING OPTICALLY ACTIVE ENDO-7- OXABICYCLO[2.2.1]HEPT-5-ENE-2-CARBOXYLIC ACID

摘要

PROBLEM TO BE SOLVED: To provide a method for producing optically active endo-7- oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid with a simple process in high yield on an industrial scale at a low cost. SOLUTION: A mixture of endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid (+)-isomer (I) and (-)-isomer (II) is treated with an optically active amine (III) (R1 is H, an alkyl or an aralkyl; R2 is an alkyl or an aralkyl; R3 is H or an alkyl; (n) is 0 or 1; and the mark * shows an asymmetric carbon atom) to form a mixture of diastereomer salts. The diastereomer salt mixture is optically resolved by the fractional recrystallization using water as the solvent and the product is treated with an acid to obtain optically active (+)-isomer (I) or (-)-isomer (II).