Synthesis of 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines and 2-(3-hydroxybutyl)-1-pyrroline using alpha-lithiated 2-methyl-1-pyrroline

D'hooghe, Matthias; Abbaspour Tehrani, Kourosch; De Kimpe, Norbert

doi:10.1016/J.TET.2009.02.050

Title

Synthesis of 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines and 2-(3-hydroxybutyl)-1-pyrroline using alpha-lithiated 2-methyl-1-pyrroline

Author

D'hooghe, Matthias

Abbaspour Tehrani, Kourosch

De Kimpe, Norbert

Abstract

Condensation of 2-methyl-1-pyrroline with chloroacetone or 3-chloro-2-butanone using LDA in THF afforded novel 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines via a peculiar reaction mechanism instead of the anticipated 2-(3-oxobutyl)-1-pyrrolines. The intermediacy of 2-(2,3-epoxy-2-methylalkyl)-1-pyrrolines in the latter transformation was demonstrated by immediate reductive epoxide ring opening utilizing lithium aluminium hydride in diethyl ether. Furthermore, 2-(3-oxobutyl)-1-pyrroline was prepared via an alternative approach through alkylation of 2-methyl-1-pyrroline with 3-chloro-2-(methoxymethyloxy)-1-propene using LDA in THF, followed by acid hydrolysis. Reduction of 2-(3-oxo butyl)-1-pyrroline by sodium borohydride in methanol afforded the corresponding 2-(3-hydroxybutyl)-1-pyrroline in good yield. (C) 2009 Elsevier Ltd. All rights reserved.

Language

English

Source (journal)

Tetrahedron. - Oxford, 1957, currens

Publication

Oxford : 2009

ISSN

0040-4020 [print]

1464-5416 [online]

DOI

10.1016/J.TET.2009.02.050

Volume/pages