Cis-3 and 3,5-substituted pyrrolizidines can be prepared from β-enaminolactones. Substituted pyrrolidinoketones lead to these compounds by an amino reductive annelation with a low diastereomeric excess, but a best access to these azabicycles consists in preparing cis-2,5-disubstituted pyrrolidines which are then transformed into the expected heterocycles.
Synthesis of 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines and 2-(3-hydroxybutyl)-1-pyrroline using α-lithiated 2-methyl-1-pyrroline
作者:Matthias D'hooghe、Kourosch Abbaspour Tehrani、Norbert De Kimpe
DOI:10.1016/j.tet.2009.02.050
日期:2009.5
demonstrated by immediate reductive epoxide ringopening 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-oxobutyl)-1-pyrroline by sodium borohydride in methanol afforded