METHOD FOR PRODUCING ASTAXANTHIN AND CANTHAXANTHIN INTERMEDIATE PRODUCTS

摘要

The invention relates to a method for producing cyclohexenone derivatives of general formula (I), wherein R¹ represents hydrogen or OH; R² represents (Ia), comprising the following steps: (a) hydrolyzing a cyclohexenol compound of formula (II), wherein R³ represents hydrogen and R⁴ represents C₁-C₆-alkoxy or R³ and R⁴ represent vicinal hydroxy groups, which carry a common acetal protective group or a ketone protective group, R⁵ represents (IIa), and R⁶ represents a protected hydroxy group, in the absence of an organic solvent and in the presence of an acid catalyst; and; (b) extracting the reaction mixture by using a polar extracting agent.