Behaviour of 2- p-tolylsulfinyl cyclohexanols under the pummerer reaction conditions

Abstract

The reactions of the chiral 2- p-tolylsulfinyl cyclohexanols with Ac 2O/NaOAc (or (CF 3CO) 2O/Py) at r.t. yielded the 2- p-tolylsulfenyl-2-cyclohexenyl acetates, which cannot be hydrolyzed into the α-hydroxyketones. The 1-methyl-2- p-tolylsulfinylcyclohexanols evolved with (CF 3CO) 2O/Py into the 3-methyl-2- p-tolylsulfenyl-2-cyclohexenyl trifluoroacetates, the latter resulting from a very highly stereoselective hetero-Claisen rearrangement (e.e.97%) of the initially formed 1-methyl-2- p-tolylsulfenyl-2-cyclohexenyl trifluoroacetates.