M. Yoshimatsu et al., STEREOSPECIFIC SYNTHESES OF XY-2-((PHENYLCHALCOGENO)METHYLENE)TETRAHYDROFURANS, Journal of organic chemistry, 61(23), 1996, pp. 8200-8206
2-Ethoxy-4-(phenylchalcogeno)but-3-ynyl ketones 1-10 were reduced with
LiBH4 in Et(2)O diastereoselectively to give 5-(phenylchalcogeno)pent
-4-yn-1-ols 11-20. Treatment of the phenylchalcogen-substituted alkyny
l alcohols 11-20 with t-BuOK in t-BuOH provided useful Z)-2-((phenylch
alcogeno)methylene)tetrahydrofurans 21-31 stereoselectively.