名称:
Chemistry of Ethanediyl S,S-Acetals - 4. Promising Way to Cis-Substituted Olefins, Stereoselectively from Carbonyl Compounds
摘要:
Aldehydes and methyl ketones readily afford 5,6-dihydro-1,4-dithiins that can be converted by n-butyllithium into their corresponding sulfur stabilized carbanions. Coupling of the latter with alkyl halides leads to species having a cis-configurated, disubstituted double bond tied up by the sulfur-containing ring which is known to be susceptible of selective removal.