PRODUCTION OF 3,5,6-TRIHYDROXYHEXANOIC ACID DERIVATIVE

摘要

PURPOSE:To effectively and economically produce the subject compound useful as an intermediate for antihyperlipemic agents by reacting a butyronitrile derivative and an alpha-haloacetic acid ester in the presence of zinc and/or zinc-copper and then reducing the resultant reaction product. CONSTITUTION:A butyronitrile derivative expressed by formula I (P<1> and P<2> are H or protecting group of OH or together form a ring) is reacted with an alpha-haloacetic acid ester expressed by formula II (X is halogen; R is alkyl) in the presence of zinc and/or zinc-copper to provide a keto-acid derivative expressed by formula III, which is then reduced to afford a 3,5,6- trihydroxyhexanoic acid derivative expressed by formula IV. All the hydroxyl groups in the resultant compounds expressed by formula IV are then protected to afford a compound expressed by formula V (Q<3> is selectively eliminative masking group of OH; Q<1> and Q<2> are masking groups of hydroxyl radical). Only the masking group Q<3> is selectively eliminated to afford a compound expressed by formula VI in which only the two secondary groups at the 3- and 5-positions are protected.