关键词: 光化学反应, 选择性, 苯基丙烯酸, 肟, 环加成反应, 电子效应, 分子轨道理论, 过渡态理论, 热化学, 取代基效应, 苯乙烯 P, 硝酮

The substituent effects on the reactivities and the regioselectivities of the title reactions were examined by chromatog. methods. On irradiation by a Hg lamp at l ?02 nm, nitrones, e.g., CHPh:N(O)(CH2)3CH:CH2, gave oxaziridine I. I rearranged further to BzNH(CH2)3CH:CH2 (II) at l ?70 nm. Upon heating, II was transformed back to the nitrone and subsequently cyclized to give III and IV.

Key words: PHOTOCHEMICAL REACTION, SELECTIVITY, PHENYLACRYLIC ACID, OXIME, CYCLOADDITION REACTION, ELECTRONIC EFFECT, MOLECULAR ORBITAL THEORY, TRANSITION STATE THEORY, THERMOCHEMISTRY, SUBSTITUENT EFFECT, STYRENE P, NITRONE