PURPOSE: To obtain a carotene compound useful as a food additive, etc., in high purity and yield and in a short process by reacting two specific compounds with each other in the presence of a base and a palladium complex and subsequently subjecting the reaction product to desulfonation reaction.
CONSTITUTION: This carotene compound of formula III (e.g. β-carotene) is obtained by reacting (A) a compound of formula I (R1 and R2 are each H, a hydroxy group or an oxo group; R is a hydrocarbon group) (e.g. retinyl p-tolyl sulfone) with (B) a compound of formula II [X is an acyloxy or a group of the formula OSO2R" (R" is a hydrocarbon group)] (e.g. vitamin A acetate) in the presence of (C) a base (preferably sodium bicarbonate, sodium carbonate, etc.) and (D) a palladium complex (preferably a tertiary phosphine palladium complex) and subsequently subjecting the reaction product to desulfonation reaction. Further, the component C is used about 1-5 equivalents based on the component A, preferably about 1-3 equivalents, and the component D is used about 0.001-1 equivalent based on the component B, preferably about 0.01-0.1 equivalent.
KANEKO TATSUHIKO
KASHIWA KENICHI
