To efficiently obtain the subject compounds useful as a medicine or a feed-additive by heating a specific cis-vitamin A compounds in the presence of a palladium-carbon catalyst.

(A) A 11-cis-vitamin A compound of formula I [Z is formyl, a group of the formula: CH2OX (X is H or an acyl) or the like] (for example, 11-cis-vitamin A acetate) is heated in the presence of (B) a palladium-carbon catalyst preferably carrying the palladium in an amount of 5-15 wt.% in (C) a solvent, usually n-heptane, preferably at a temp. of 80-105°C to obtain the objective compound of formula II. The components B and C are preferably used in amounts of 0.5-10 wt.% and 100-2,000 wt.%, respectively, based on the amount of the component A. The reaction is preferably performed in an atmosphere of an inert gas such as nitrogen gas.