Reactions of oxathio-substituted crotyllithium with alkyl halides and carbonyl compounds. An example of an ambident nucleophile

Article abstract of DOI:10.1016/S0040-4020(01)88769-X

The lithiated anion (2), obtained by treatment of 2-(-propenyl)-1,3-oxathiane (1) with sec-BuLi, reacts with alkyl halides yielding substitution products predominantly at the α terminus; on the contrary, carbonyl compounds afford addition products at they γ terminus. The γ-adducts readily cyclize to spiro oxathianes.