A new method for the deoxygenation of secondary alcohols

Abstract

On reaction with tributylstannane, O-cycloalkyl thiobenzoates and O-cycloalkyl S-methyl dithiocarbonates, derived from secondary alcohols, give good yields of the corresponding hydrocarbons. The mechanism of this planned reaction is radical in character and thus rearrangements common in carbocation reactions are avoided. The particular applicability of this procedure in sugar chemistry is illustrated. The reaction takes place under neutral conditions compatible with the presence of the functional groups which normally occur in aminoglycoside antibiotics. A convenient general synthesis of O-cycloalkyl thioesters has been developed which gives access to O-cycloalkyl thioformates and thioacetates. An extension of this method affords the hitherto unknown O-cycloalkyl seleno-formates and selenobenzoates. An attempted extension of the method to the synthesis of O-chloesteryl tellurobenzoate gave, unexpectedly, a good yield of benzyl cholesteryl ether.