Tetrahedron

Differences in rates of Diels-Alder reactions as experimental indicators of synchronous or asynchronous transition states

RN Buckle, PY Liu, EWD Roberts, DJ Burnell

Index: Buckle, Ronald N.; Liu, Pei-Ying; Roberts, Evan W. D.; Burnell, D. Jean Tetrahedron, 1999 , vol. 55, # 38 p. 11455 - 11464

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Citation Number: 11

Abstract

Assessment of the relative rates of the Diels-Alder reactions of the unsymmetrical diene 2- (trimethylsilyloxy)-1, 3-cyclohexadiene (1) and its 6, 6-and 5, 5-dimethyl analogs 2 and 3 indicated that with symmetrical, ethylenic dienophiles (para-benzoquinone, maleic anhydride and N-phenylmaleimide) the Diels-Alder reaction is almost synchronous, but with tetracyanoethylene and with diethyl acetylenedicarboxylate the addition is sufficiently ...