An improved synthesis of β-hydroxysulfones via <i>α</i>-sulfonylcarbanions in liquid ammonia. The direct metalation of dialkyl and aryl alkyl sulfones

Abstract

Dimethyl sulfone, methyl p-tolyl sulfone, ethyl p-tolyl sulfone, benzyl p-tolyl sulfone, and tetrahydrothiophene 1,1-dioxide were rapidly and quantitatively metalated by lithium amide (or potassium amide) in liquid ammonia, and the resulting organometallic compounds were added to a variety of carbonyl compounds to form the corresponding β-hydroxysulfones in good to excellent yields. The advantages of this method are speed, convenience, and versatility. Possible reasons for the failure of 1-phenyl-1-(p-tolylsulfonyl)methyllithium (XVIII) to form β-hydroxysulfones are discussed.