Applications of nitroalkene (4+2); cycloaddition chemistry. The asymmetric synthesis of substituted pyrrolidines and the total synthesis of mesembrine

A general route for the preparation of 2,2-disubstituted 1-nitroalkenes has been developed. Conjugate 1,4-addition of zinc cuprates (RCu(CN)ZnI) to easily obtained (E)-1-nitroalkenes, followed by trapping with phenylselenenyl bromide, and subsequent oxidative elimination afforded the corresponding 2,2-disubstituted 1-nitroalkenes in 76-88% yield as E/Z isomeric mixtures ($\sim$1.0/1.5, E/Z). 2,2-Disubstituted-1-nitroalkenes were found to undergo Lewis acid-promoted (4+2) cycloadditions with n-butyl vinyl ether to afford cyclic nitronates in 76-90% yield. The resulting nitronates were reduced with hydrogen in the presence of platinum oxide to afford 3,3-disubstituted pyrrolidines which were isolated in 70-83% yield as their N-tosyl derivatives. Similarly, cycloadditions of (E)-2-nitrostyrene with 2-substituted enol ethers provided for the stereoselective synthesis of cis- and trans-3,4-disubstituted pyrrolidines.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Marcin, Lawrence R.

Contributors dc:contributor

• Denmark, Scott E.

• Chemistry, Organic

Statement dc:rights

• Copyright 1996 Marcin, Lawrence R.

Language dc:language

eng

Identifier

9780591199345
AAI9712369
(UMI)AAI9712369

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20131