1 -Ethylpyrrolidines, from

Show how to synthesize A-ethylpyrrolidine from pyrrolidine using acylation-reduction. 

Hydroxypyrrolidine (14), a colorless oil, is readily obtained from 1-ethylpyrrolidine by conversion to the 1-oxide and then heating to split out ethylene. Direct oxidation of pyrrolidine by performic acid gave only a 1% conversion (59CB1748). Oxidation of 14 with mercuric oxide now gave 1-pyrroline 1-oxide 15 as a distillable liquid. Phenylmagnesium bromide added across the dipolarophilic system of 15 yielded l-hydroxy-2-... 

Specific base-solvent combinations have been shown to control the orientation of 1,2-eliminations from AT-chloro-2-ethylpyrrolidine to give substantial proportions of the previously unreported 5-ethyl-l-pyrroline (39). The results clearly establish the utility of base-promoted elimination reactions for the preparation of previously unavailable cyclic imines. 

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