Simultaneous Synthesis of Both Rings of Chromenes via a Benzannulation/o-Quinone Methide Formation/Electrocyclization Cascade

N Majumdar, KA Korthals, WD Wulff

Index: Majumdar, Nilanjana; Korthals, Keith A.; Wulff, William D. Journal of the American Chemical Society, 2012 , vol. 134, # 2 p. 1357 - 1362

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Citation Number: 44

Abstract

A new route to the chromene ring system has been developed which involves the reaction of an α, β-unsaturated Fischer carbene complex of chromium with a propargyl ether bearing an alkenyl group on the propargylic carbon. This transformation involves a cascade of reactions that begins with a benzannulation reaction and is followed by the formation of an o-quinone methide, and finally results in the emergence of a chromene upon an electrocyclization. ...