Chemistry of ketene acetals. 7. 2-Methoxy-4H-pyrans as strong hydride donors in reactions with electrophilic olefins

…, C Hazen, JW Scheeren, RJF Nivard

Index: Bakker, C. G.; Hazen, C. J. J. M.; Scheeren, J. W.; Nivard, R. J. F. Journal of Organic Chemistry, 1983 , vol. 48, # 16 p. 2736 - 2742

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Citation Number: 3

Abstract

The reactions of 2-methoxy-5, 6-dihydropyrans (2) and 2-methoxy-4H-pyrans (3) with a variety of electrophilic olefins R4R5C= C (CN) X have been studied. Cyclobutanes are formed in an equilibrium reaction from 2 as well as 3. In general, the compounds 3 give ultimately the thermodynamically stable heptadienoic esters 10. 2-Methoxy-4H-pyrans, substituted at carbon atom 6, yield, however, a pyrone derivative (11) when they react with ...