Dimerization and Intermolecular Cycloaddition Reactions

A review of the influence of substituent effects on photochemical cycloaddition reactions has been published.154 Another short review on photocycloaddition reactions has also appeared.155 

Two studies of the addition of olefins to 9-cyanophenanthrene have been reported.165 167 Mizuno et al. have examined the addition of the olefins (234a—e) 

A previous publication of the attempted photoaddition of fumaric acid to stilbene reported the failure of the reaction.1 2 Green and Retjo1 8 have reexamined the reaction and have found that a 46% yield of the diester (238) of / -truxinic acid is obtained when / / -stilbene is irradiated (Pyrex) in benzene solution with dimethyl fumarate. Trace amounts of dimethyl 8-truxinate (239) and dimethyl neo-truxinate (240) are also formed. 

A full report of the photochemical addition of 1,3-diphenylisobenzofuran to cycloheptatriene has been made.1 4 196 The 0-acetonaphthone-sensitized addition of cis- and trans-1 -chloropropene to cyclopentadiene has been reported in detail.1 167 The isomer distribution was shown to be temperature dependent. 182 183 185 187 

---