1,3-Dimethoxy-5-methylene-1,3-cyclohexadiene Compounds with Leaving Groups at C6: Generation, Solvolytic Reactivity, and Their Importance in the Photochemistry of 3,5-Dimethoxybenzyl Derivatives
作者:D. P. DeCosta、N. Howell、A. L. Pincock、J. A. Pincock、S. Rifai
DOI:10.1021/jo000387o
日期:2000.7.1
photolysis. The isomeric triene, 5-methylene-1,3-cyclohexadiene derivative was observed for the acetate (2a), diethyl phosphate (2e) and trimethylammonium chloride (2f). The solvolysis of these derivatives, 2, was examined in alcohol solvents and the rate correlation with YOTS values gave m = 0.47 (2a) and 0.63 (2e), suggesting SN1 reactivity but with an early transition state. Quantum yields for formation
3,5-二甲氧基苄基化合物的光化学性质为以乙酸根(1a),氯化物(1b),溴化物(1c),碘化物(1d),磷酸二乙酯(1e)和三甲胺(1f)作为氯化物。经过产品研究和快速光解法的检验。观察到乙酸(2a),磷酸二乙酯(2e)和三甲基氯化铵(2f)的异构体三烯,5-亚甲基-1,3-环己二烯衍生物。在乙醇溶剂中检查了这些衍生物2的溶剂分解,其与YOTS值的速率相关性得出m = 0.47(2a)和0.63(2e),表明SN1具有反应性,但具有早期过渡态。形成2a和2e的量子产率表明,这些三烯在相应的芳基甲基底物的总体光化学中仅起次要作用(约16%)。