The 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloro-2-cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound
新合成了6-
氯-2-
环己烯酮3、6和11以及5-
氯-
2-环戊烯酮15。用化合物3和15在烯烃的光环加成中获得的结果表明,通过在烯酮的α′-位用
氯取代弗洛林,降低了氧杂
环丁烷与
环丁烷的产物比。在分子内的光环加成6中没有形成氧杂
环丁烷。化合物11不光加成至烯烃中。新合成的2-
氯-3-
环己烯酮8和9它们在λ= 366 nm的光下也是光稳定的,但是
戊烷中的π-π*激发(λ= 254 nm)导致形成
4,4-二甲基环己酮(29)。