PRODUCTION OF YNOL THIOETHER

PROBLEM TO BE SOLVED: To obtain the subject compound useful as an available intermediate, by reacting a 1-butyn-3-ol with a specific sulfenyl halide in the presence of a base and then reducing the reaction product or deprotecting and reducing. SOLUTION: 1-Butyn-3-ol (e.g. optically active substance) is reacted with a sulfenyl halide of the formula R SX (R is a lower alkyl, an aryl, etc.; X is a halogen) (e.g. phenylsulfenyl chloride) in the presence of a base (an alkyllithium or an alkylmagnesium halide such as n-butyllithium) to form an ynol thioether of formula I, which is reduced or deprotected and reduced to give the objective compound of formula II (R is H or an OH-protecting group or an alkyl-containing silyl such as trimethylsilyl or t-butylmethylsilyl).