Synthesis and Intramolecular [4+2] Cycloaddition Chemistry of Trienes Tethered with an Ether Linkage

Donald Craig; John C. Reader

doi:10.1055/s-1992-21484

Synlett 1992; 1992(9): 757-758
DOI: 10.1055/s-1992-21484

letter

© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Synthesis and Intramolecular [4+2] Cycloaddition Chemistry of Trienes Tethered with an Ether Linkage

Donald Craig^* , John C. Reader

^*Department of Chemistry, Imperial College of Science, Technology and Medicine, London SW7 2AY, England

Abstract

PDF Download All articles of this category

Trienes 4a-d [e.g., methyl 4-(1,1-dimethyl-3,5-hexadienyloxy)crotonate, 4a] have been synthesized via trimethylsilyl trifluoromethanesulfonate mediated reactions of dienophile-derived acetals 2a-d with (E)-1-(trimethylsilyl)-2,4-pentadiene. Thermolysis of 4 gives the corresponding intramolecular cyclo-adducts 5-8 (e.g., methyl 3,3-dimethyl-3,4,4a,7,8,8a-hexahydro-1H-2-benzopyran-8-carboxylate, 5) in excellent yield. The selectivities of the internal [4+2] cycloaddition processes are rationalized in terms of (i) a chair-like conformation of the diene-dienophile linking chain, and (ii) the steric bulk of the phenylsulfonyl group.

PDF (161 kb)