Synthesis of pterocarpans by means of a "disfavored" 5-endo-trig radical cyclization reaction

Santhosh, Kalpathy Chidambareswaran ; Gopalsamy, Ariamala ; Balasubramanian, Kalpattu Kuppusamy (2001) Synthesis of pterocarpans by means of a "disfavored" 5-endo-trig radical cyclization reaction European Journal of Organic Chemistry, 2001 (18). pp. 3461-3466. ISSN 1434-193X

Full text not available from this repository.

Official URL: http://www3.interscience.wiley.com/journal/8500924...

Related URL: http://dx.doi.org/10.1002/1099-0690(200109)

Abstract

A successful synthesis of pterocarpans 1, based on a "disfavored" 5-endo-trig radical cyclization reaction, has been accomplished. The radical precursor 4-(2'-bromoaryloxy)-2H-chromene 8 was synthesized in six steps, starting from aryl propynyl ether 2. On treatment with tributyltin hydride in refluxing benzene, aryl enol ether 8 underwent radical cyclization to furnish the pterocarpan 1. A deuterium label study was performed to prove the occurrence of 5-endo-trig radical cyclization. This methodology was extended further to synthesize a class of hitherto unknown pterocarpans 13. A novel and stereoselective route towards the synthesis of aryl ethers of bromohydrins by means of the Mitsunobu reaction is also described.

Item Type:Article
Source:Copyright of this article belongs to John Wiley and Sons, Inc.
Keywords:Cyclizations; Heterocycles; Natural Products; Radical Reactions; Reaction Mechanisms
ID Code:3704
Deposited On:18 Oct 2010 09:59
Last Modified:12 Jan 2011 07:26

Repository Staff Only: item control page