METHOD FOR PRODUCING DIPLOID OF CYCLIC LACTIC ACID OLIGOMER

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a cyclic lactic acid oligomer, with which a cyclic lactic acid oligomer becoming a diploid in terms of a chain lactic acid oligomer of a starting raw material is obtained in a high yield. SOLUTION: The method for producing a 2m-mer of a cyclic lactic acid oligomer comprises (i) reacting an m-mer of a chain lactic acid oligomer having m (m is an integer of 2-30) constituent units derived from lactic acid with a carboxylic acid or a carboxylic acid derivative represented by the formula: R1COX and then (ii) subjecting the obtained reaction product to cyclization reaction in an organic solvent at 0-30°C. A 2m-mer of a cyclic lactic acid oligomer of a diploid in terms of the m-mer of a chain lactic acid oligomer of a starting raw material is selectively formed and a cyclic lactic acid oligomer mixture having a specific composition comprising a large amount of the 2m-mer of the cyclic lactic acid oligomer is obtained. COPYRIGHT: (C)2005,JPO&NCIPI