α-Methoxycarbamate 12, synthetic precursor of the 2,6-disubstituted alkaloids of Sedum acre, was obtained in high yield from 2-phenacylpiperidine 5; the key step of the synthesis rests on the anodic methoxylation, which allows the functionalization of carbon 6. Nucleophilic substitution of the methoxy group by an acetonyl chain leads, after the required transformations, to sedinone 23. Bromomethoxylation of the enecarbamate 19 followed by dehydrohalogenation and nucleophilic substitution of the methoxy group leads to sedacrine 33. In both cases, the nucleophilic substitution of the methoxy group leads to a cis 2,6-disubstituted piperidine derivative. Key words: synthesis, piperidine alkaloids, anodic methoxylation
α-甲氧基羰酸酯12,是Sedum acre的2,6-二取代生物碱的合成前体,从2-苯乙酮哌啶5中高收率得到;合成的关键步骤在于阳极甲氧基化,这允许对碳6进行官能化。通过乙酰基链的亲核取代将甲氧基取代,经过必要的转化后,得到sedinone 23。对烯基羰酸酯19进行溴甲氧基化,随后进行脱卤代和甲氧基团的亲核取代,得到sedacrine 33。在这两种情况下,甲氧基的亲核取代导致了顺式2,6-二取代哌啶衍生物的形成。关键词:合成、哌啶生物碱、阳极甲氧基化。