Parallel mechanisms for the cycloaromatization of enyne allenes†

TS Hughes, BK Carpenter

Index: Hughes, Thomas S.; Carpenter, Barry K. Journal of the Chemical Society. Perkin Transactions 2, 1999 , # 11 p. 2291 - 2298

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Citation Number: 28

Abstract

The Myers–Saito cycloaromatization of enyne allenes is proposed to consist of two parallel mechanisms, one involving a biradical and the other with dipolar character. MCSCF calculations suggest that a nonplanar cyclic allene could be fairly close in enthalpy to the biradical, while the planar zwitterion originally proposed as a possible second intermediate is in fact a transition state for the interconversion of the two enantiomeric cyclic allenes. ...