Unusual ring opening of a Cyclopropylideneamine derivative during a favorskii-type rearrangement of α-Chloroketimines
1986; Elsevier BV; Volume: 42; Issue: 1 Linguagem: Inglês
10.1016/s0040-4020(01)87403-2
ISSN1464-5416
AutoresNorbert De Kimpe, M. D. Palamareva, Paul Sulmon, Roland Verhé, L. DE BUYCK, N. Schamp, Jean-Paul Declerco, Bernard Tinant, M. Van Meerssche,
Tópico(s)Synthesis and Reactivity of Heterocycles
ResumoThe reaction of N-(3-chloro-3-methyl-2-butylidene)amines (i.e. α-chloroketimines) with lithium diisopropylamide in tetrahydrofuran gave rise to an unexpected reaction leading to 2-(N-alkylimino)-3,3-dimethyl-1-isopropyl-5-(2-methylpropylidene) pyrrolidines in good yields. The reaction mechanism is interpreted in terms of a Favorskii-type 1,3-dehydrochlorination affording intermediate cyclopropylideneamines (N-analogues of cyclopropanones), which “dimerize” in an unusual way. This mechanism entails a “normal” opening as well as an “abnormal” opening of incipient cyclopropylideneamine adducts. This rearrangement represents an example of the scarcely reported abnormal opening of functionalized cyclopropylamines.
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