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Reduction of simple β-keto sulfides, β-keto sulfoxides and P-keto sulfones by an actively fermenting mutant of Saccharomyces cerevisiae proceeds readily and affords good yields of the corresponding optically active secondary alcohols. For example, 1-(benzylthio)propan-2-one gave optically pure (S)-(+)-1-(benzylthio)propan-2-ol and 1- (phenylsulfonyl)propan-2-one gave optically pure (S)-(+)-1- (phenylsulfonyl)propan-2-ol. In the reductions of racemic β-keto sulfoxides the enantiomers were reduced at sufficiently different rates to enable isolation of an optically active ketone and of an optically active β-hydroxy sulfoxide. Hence, 1-(phenylsulfinyl)propan-2-one gave (S)-(-)-1-(phenyl-sulfinyl)propan-2-one and (RS,SC)-(+)-1- (phenylsulfinyl)propan-2-ol.

Reimer-Tiemann formylations of oestradiol and oestrone were investigated and, whilst substitution was effected under certain conditions to give mixtures of 2- and 4-formyloestrogens, yields were very low and the method was unsuitable for preparative purposes. Regioselective methods were developed and 2-formyloestradiol was conveniently prepared from oestradiol by formylation of the lithio derivative of the bis(methoxymethyl) ether and removal of the rotecting groups with hydrochloric acid. 4-Formyloestradiol was prepared by a sequence of reactions starting with the methoxyethyl ether of 4-bromooestradiol, then metal-halogen interconversion, formylation with N-methylformanilide, and removal of the protecting group. A number of related derivatives, including 2-formyloestriol, were prepared.

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α- and β-Keto esters and amides are readily reduced by an actively fermenting mutant of Saccharomyces cerevisiae and produce optically active α- and β-hydroxy esters and amides in moderate yields. Typically, methyl 2-oxo-2-phenylacetate gave methyl (R)-(-)-2-hydroxy- 2-phenyl- acetate; 2-oxo-2-phenylacetamide gave (R)-(-)-2-hydroxy-2- phenylacetamide; ethyl benzoylacetate gave ethyl (S)-(-)-3-hydroxy-3- phenylpropionate, and ethyl 2-oxocyclohexanecarboxylate gave ethyl (1R,2S)-(+)-2-hydroxycyclohexanecarboxylate. In each case, the product obtained was optically pure. However, the reduction of ethyl pyruvate to ethyl lactate produced partially racemized products.