The Stereochemistry of the Thermal Cheletropic Decarbonylation of 3-Cyclopentenone As Determined by Multiphoton Infrared Photolysis/Thermolysis
作者:Gregory R. Unruh、David M. Birney
DOI:10.1021/ja0353661
日期:2003.7.1
cheletropic decarbonylation of 3-cyclopentenone. The stereochemistry of decarbonylation of an unconstrained derivative (trans,trans-2,5-dimethyl-3-cyclopentenone, 4) has been determined for the first time. Under conventional pyrolysis conditions, thermal rearrangements of the initial product (trans,trans-2,4-hexadiene, 5) occur at the high temperatures required for the decarbonylation. However, by
3-环戊烯酮的热螯合脱羰有两种允许的途径。首次确定了无约束衍生物(反式,反式-2,5-二甲基-3-环戊烯酮,4)脱羰的立体化学。在常规热解条件下,初始产物(反式,反式-2,4-己二烯,5)在脱羰所需的高温下发生热重排。然而,通过使用多光子红外光解/热解来启动脱羰,表明 4 的热脱羰的初始产物仅为一氧化碳和立体定向 5。因此,脱羰的立体化学是旋转的,与先前的理论研究一致。对晶体结构的调查也揭示了沿该反应坐标的基态畸变。