Sur l'aptitude à l'extension du noyau pipéridique en fonction de la substitution de l'atome d'azote: réaction du diazométhane avec quelques pipéridones-4 et désamination nitreuse des aminométhyl-alcools correspondants

Abstract

Aptitude to ring expansion in the piperidine series, measured by the ratio of ring expanded ketone to epoxide, varies considerably according to the nitrogen atom substituent. This ratio is essentially the same in the case of the reaction of diazomethane on 4-piperidones and the nitrous acid deamination of the corresponding aminoalcohols. The values of the ratio are 0.01–0.1 for a phenylsulfonyl group, of the order 0.3–0.6 for a benzoyl group and slightly greater than 1 for a benzyl group. Electronic effects (inductive and field effects) are the cause of these differences. Parallels between the two reactions indicate that nucleophilic attack of diazomethane on the carbonyl group can lead to the ring expanded ketone and the epoxide.