PURPOSE: To produce the subject compds. useful as a source material for the synthesis of pharmaceutics in high yield with a high enantiomer excess from L- and D-lactic acid ester through the four-step reaction of protection of org. OH, reduction, Wittig reaction and removal of a protecting group.

CONSTITUTION: An alkylester of (S)- or (R)-lactic acid expressed by formula II (R3 is an alkyl) is reacted with a compd. expressed by the formula R1X (X is a leaving group; R1 is an alkyl) or formula R'1 (R'1 is a compd. which can form an ether functional group by adding to butenol) to obtain a compd. expressed by formula III. Then the compd. is reduced into a compd. expressed by formula IV, and further reacted with a Wittig reagent (preferably triphenylmethylphosphonium iodide) to obtain a compd. expressed by formula VI. At least, the protecting group R1 is removed from the alkenol deriv. expressed by formula VI to obtain (S)- or (R)-1-buten-3-ol expressed by formula I. The compd. of formula I is useful as a source material for the synthesis of pharmaceutically active compds. which belong to 1-buten-3-ols.