[6+3] cycloaddition of pentafulvenes with 3-oxidopyrylium betaine: a novel methodology toward the synthesis of 5-8 fused oxabridged cyclooctanoids

Title[6+3] cycloaddition of pentafulvenes with 3-oxidopyrylium betaine: a novel methodology toward the synthesis of 5-8 fused oxabridged cyclooctanoids
Publication TypeJournal Article
Year of Publication2006
AuthorsK. Krishnan, S, Sajisha, VS, Anas, S, Suresh, CH, Bhadbhade, MM, Bhosekar, GV, Radhakrishnan, KV
JournalTetrahedron
Volume62
Issue25
Pagination5952-5961
Date PublishedJUN
Type of ArticleArticle
ISSN0040-4020
Keywordsfulvenes, oxabridged cyclooctanoids, oxidopyrylium betaine, [6+3] cycloaddition
Abstract

Pentafulvenes undergo a facile [6+3] cycloaddition with 3-oxidopyrylium betaine, generated from the corresponding pyranulose acetate, leading to the formation of 5-8 fused oxabridged cyclooctanoids. The product is formed by a [6+3] cycloaddition, followed by a 1,5-hydrogen shift of the initially formed [6+3] adduct. The reaction was found to be general and a number of fulvenes with a wide range of substituents at the exocyclic double bond, that is, at the C6 position followed a similar reactivity pattern. The [6+3] adduct, a 5-8 fused oxabridged cyclooctanoid, is potentially amenable to a number of synthetic transformations due to the presence of an alpha, beta-unsaturated ketone and cyclopentadiene part. By selecting appropriately substituted fulvene and pyranulose acetates, it is possible to use this methodology for the synthesis of a wide range of 5-8 fused cyclooctanoids. The experimental results have been rationalized on the basis of theoretical calculations. (c) 2006 Elsevier Ltd. All rights reserved.

DOI10.1016/j.tet.2006.04.017
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

2.645

Divison category: 
Biochemical Sciences
Center for Material Characterization (CMC)