Pyrano-sultone: a novel binuclear heterocyclic system
Abstract
Reaction of the α-keto alcohol (1) with MeSO2Cl–Et3N–CH2Cl2 gives, in addition to the keto sulphonate (2), the unsaturated sultone (3) the relative amounts of which vary with temperature; when pyridine is the proton acceptor, the sultone is not formed, and hydrogenation gives the saturated sultone (5) exclusively.