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The sulphenylated phosphine oxides Ph,P(0)*CH(SR2) R1, easily prepared from triphenylphosphine, diphenyl or dimethyl disulphide, and an alkyl halide, form anions which act as acyl anion equivalents. Reaction with aldehydes and ketones gives vinyl sulphides, which can be hydrolysed to carbonyl compounds. Reaction with a-phenylthioand cc-methoxy-aldehydes and ketones gives enone precursors. The scope and limitations of the method are described.CONVENTIOKAL ketone syntheses involve the addition of ponding to this approach. Recently a new family of a carbon nucleophile (Grignard reagent, enolate anion, ketone syntheses has been evolved using the same etc.) to a carbon electrophile (usually an acyl derivative), disconnection but with umpolung [equation (ii)] so the electrophilic carbon atom becoming the new carbonyl that the new carbonyl carbon atom is derived from the carbon*2 Equation (i) shows the disconnection 'Orre'-

The development of a commercial manufacturing route for (S)-β-phenylalanine 8, a key pharmaceutical building block, is described. The different approaches which were investigated, based on catalytic asymmetric hydrogenation of enamide intermediates and on biocatalysis using acylase and lipase hydrolyses, are compared. The lipase resolution route was chosen for scaleup, and the final two-step process, based on readily available raw materials, is shown to be robust at full manufacturing scale

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