Process for producing enyne Derivatives

The invention relates to compounds of the formula wherein R is a hydrogen atom, a lower alkyl group, a halo lower alkyl group, a lower alkenyl group, a lower alkynyl group or a cycloalkyl group; R is a hydrogen atom or a group of the formula wherein each of R , R and R , which may be the same or different, is a hydrogen atom or a lower alkyl group, each of R , R , R and R , which may be the same or different, is a hydrogen atom, a halogen atom, a hydroxyl group, a lower alkyl group or a lower alkoxy group, and R is a hydroxyl group, a halogen atom, a group of the formula B-O (wherein B is a protecting group for a hydroxyl group), a hydroxy methyl group, a formyl group, a carboxyl group, a lower alkoxy carbonyl group, a lower alkanoyl group, an amino group, a mercapto group or a group of the formula R -X-Y-(wherein R is a phenyl or thienyl group which may have one or two substituents selected from the group consisting of a halogen atom, a hydroxyl group, a lower one or two substituents selected from the group consisting of a halogen atom, a hydroxyl group, a lower alkyl group, a cyano group, a lower alkoxy group and a heterocyclic group, each of X and Y, which may be the same or different, is an oxygen atom, a sulfur atom, a carbonyl group, a group of the formula -CHR- (wherein R is a hydrogen atom or a lower alkyl group) or a group of the formula -NR- (wherein R is a hydrogen atom or a lower alkyl group), or X and Y together form a vinylene group or an ethynylene group), provided that when either one of X and Y is an oxygen atom, a sulfur atom or a group of the formula -NR- (wherein R is as defined above), the other is a carbonyl group or a group of the formula -CHR- (wherein R is as defined above), and W is a halogen atom, and a process for preparing such compounds.