| abstract |
A compound of a 3,5,6-trihydroxyhexanoic acid derivative of the formula: ##STR1## wherein P 1 and P 2 are independently hydrogen atoms or hydroxy-protecting groups, or together form a ring, and R is an alkyl group is effectively prepared by a process comprising steps of: n reacting a butyronitrile derivative of the formula: ##STR2## wherein P 1 and P 2 are the same as defined above with an α-haloacetate of the formula: n n X--CH.sub.2 --COOR (III) n n wherein X is a halogen atom, and R is the same as defined above in the presence of a metallic catalyst selected from the group consisting zinc and zinc-copper to form a keto acid derivative of the formula: ##STR3## wherein P 1 , P 2 and R are the same as defined above, and then reducing the obtained keto-acid derivative of the formula (IV). |