The saturated pyrrolizidine diols. III. A partial synthesis of turneforcidine

Abstract

Turneforcidine has been prepared by the oxidation of methyl 7α-hydroxy- 8α-pyrrolizidine-1α-carboxylate to the 7-keto compound and stepwise reduction with hydrogen/platinum and lithium aluminium hydride. 7β- Hydroxy-8α-pyrrolizidine-1β-carboxylic acid is not epimerized by alkali but converted into the stable γ-lactone (VI).