188015-47-6

Upstream product

• 24424-99-5 di-tert-butyl dicarbonate 
• 51693-17-5 (S)-toluene-4-sulfonic acid 5-oxo-pyrrolidin-2-ylmethyl ester 
• 135697-21-1 (S)-(1-tert-butoxycarbonyl-5-oxopyrrolidin-2-yl)-methyl-4-methylbenzenesulfonate 

Downstream Products

• 188015-49-8 (S)-2-Methoxy-5-(toluene-4-sulfonyloxymethyl)-pyrrolidine-1-carboxylic acid tert-butyl ester 
• 214334-42-6 (2S,5S)-2-Allyl-5-(toluene-4-sulfonyloxymethyl)-pyrrolidine-1-carboxylic acid benzyl ester 
• 214334-48-2 (2R,5S)-2-Heptyl-5-(3-hydroxy-butyl)-pyrrolidine-1-carboxylic acid benzyl ester 
• 159425-05-5 (2R,5S)-2-Heptyl-5-(3-oxo-butyl)-pyrrolidine-1-carboxylic acid benzyl ester 
• 138810-08-9 (2S,5R)-1-(Carbobenzyloxy)-2-(1-hydroxypropyl)-5-methylpyrrolidine 

Relevant academic research and scientific papers

Highly stereoselective trans addition of π-type nucleophiles to a bicyclic N-acyliminium ion - Application to the synthesis of indolizidine and pyrrolizidine alkaloids

Enantiopure bicyclic 5-ethoxytetrahydropyrrolo[1,2-c]oxazol-3-one 1b was prepared in two steps from the known tosylate 4, which is readily available from (S)-pyroglutamic acid. Trapping of the N-acyliminium ion (I), generated in situ from 1b in the presence of Lewis acid, with various silylated π-type nucleophiles gave rise selectively to trans adducts 2. The usefulness of this stereoselective access to trans-2,5-disubstituted pyrrolidines was illustrated by formal syntheses of 3,5-disubstituted indolizidine toxins, starting from 5-allyltetrahydropyrrolo[1,2-c]oxazol-3-one 2a. Moreover, an enantiodivergent synthesis of the pyrrolizidine alkaloids (+) and (-)-xenovenine was achieved starting from the same chiral building block 2a.

Stereoselective access to trans-2,5-disubstituted pyrrolidine derivatives by nucleophilic addition to bicyclic N-acyliminium ion

5-Alkoxy-pyrroloxazolidin-3-ones 1 were stereoselectively prepared from (S)-pyroglutamic acid. Treatment of 1 with a Lewis acid generated in situ the N-acyliminium 2, which was trapped by various π-nuclcophiles leading selectively to trans pyrrolidine derivatives 3.