PURPOSE: To obtain the compound which is used as a dye, etc., for coloring fish pigments, etc., by halogenating a specific tertiary alcohol or the like, then converting it into a phosphonium salt by phosphines in an inert solvent and allowing it to react with dimethyl-octatrienedials.
CONSTITUTION: A tertiary alcohol of formula I or a diacetate of formula II is allowed to react with an aqueous hydrobromic acid, hydrochloric acid or the like in an inert solvent, and the produced halide of formula III (wherein X is Cl or Br) is allowed to react with triphenyl phosphine in a chain-opened dialkyl ether of the formula: R1-O-R2 (wherein R1 is 1-4C alkyl; R2 is 2-4C alkyl) to obtain triphenyl phosphonium salt of formula IV. Subsequently, from 2 to 3 mol of this phosphonium salt of formula IV is allowed to undergo Wittig reaction with 1 mol of 2,7-dimethyl-2,4,6-octatrienedials, and simultaneously or continuously, an acetyl group is allowed to leave to obtain the objective astaxanthin which is a dye highly demanded for coloration of fish pigments.
YOAHIMU PAUSUTO
BUARUTAA DOPURAA
UDO ROIDE
