Synthesis and application of N-methoxy-N-methyl-2-phenylsulfonyl- acetamide as a two-carbon homologating agent

With the well-known precedence that N-methoxy-N-methyl amides are excellent acyl cation and aldehyde equivalents, N-methoxy-N-methyl-2- phenylsulfonylacetamide (3), a new reagent, synthetically equivalent to ΘCH2CHO and ΘCH2COR was synthesised. The simplicity involved in the alkylation at the active methylene site in 3, followed by safe removal of the phenylsulfonyl group, makes 3 a versatile reagent for two-carbon homologation of alkyl halides. The method, when applied to sugar halides 6j and 6k led to the synthesis of 2,3-dideoxy sugars.