relation: http://d-scholarship-dev.library.pitt.edu/20389/
title: Asymmetric total syntheses of tuberostemonine, didehydrotuberostemonine, and 13-epituberostemonine
creator: Wipf, P
creator: Spencer, SR
description: Detailed experimental approaches toward the pentacyclic Stemona alkaloids tuberostemonine and didehydrotuberostemonine and the close analogue 13-epituberostemonine are described. The syntheses originate with a hydroindolinone derivative that can be obtained on a large scale in a single step from carbobenzoxy-protected L-tyrosine. Highlights of the conversion of this hydroindolinone to the target structures are the three-fold use of ruthenium catalysts, first in azepine ring-closing metathesis and then in alkene isomerization and cross-metathesis propenyl-vinyl exchange, as well as the stereoselective attachment of a γ-butyrolactone ring to a tetracycle core structure by use of a lithiated asymmetric bicyclo-[3.2.1]octane (ABO) ortho ester. Structural analysis by density functional theory (DFT) methods revealed that the ease of oxidation of the natural product is likely due to the conformational preferences of the pyrrolidine and the fused cyclohexane rings.
date: 2005-01-12
type: Article
type: PeerReviewed
format: text/plain
language: en
rights: attached
identifier: http://d-scholarship-dev.library.pitt.edu/20389/1/licence.txt
identifier:   Wipf, P and Spencer, SR  (2005) Asymmetric total syntheses of tuberostemonine, didehydrotuberostemonine, and 13-epituberostemonine.  Journal of the American Chemical Society, 127 (1).  225 - 235.  ISSN 0002-7863     
relation: 10.1021/ja044280k