ChemInform Abstract: Deamination Reactions. Part 50. 2‐Thia‐5‐ and ‐6‐norbornyl Cations and Their S,S‐Dioxides.

Abstract

ChemInform Abstract The effect of the S or SO2 bridges on the rearrangement of the title cations is studied. Deamination of (I) and (V) yields the exo alcohols shown in the scheme; while the former reaction proceeds via the sulfonium ion (II), the unequal deuterium distribution in (VIII)/(IX) can be rationalized by the participation of (VI) and a rather slow Wagner-Meerwein rearrangement via (VII). The cations of dioxides (XIII) (investigated instead of (X) due to an unexpected fragmentation to give (XII)) and (XIV) yield mixtures of products, containing significant amounts of alkenes besides the endo and the predominant exo alcohols. These reactions probably proceed via open cations instead of bridged structures of types (II) and (VII), thus confirming that exo selectivity of norbornyl cations cannot be regarded as a reliable criterion for a bridged intermediate.