Effects of oligooxyethylene linkage on intramolecular [2 + 2] photocycloaddition of styrene derivatives

✍ Scribed by Yosuke Nakamura; Takahiro Fujii; Seiichi Inokuma; Jun Nishimura

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 106 KB
• Volume: 11
• Category: Article
• ISSN: 0894-3230
• DOI: 10.1002/(sici)1099-1395(199802)11:2<79::aid-poc975>3.0.co;2-k

✦ Synopsis

There are two possible explanations for the high yields in the intramolecular [2 2] photocycloaddition of compounds 3a-d in which two styrene moieties are bridged by an oligooxyethylene linkage: one is the electronic effects of phenoxy oxygen atoms at the para-position of the vinyl group and the other is the steric effects due to the flexibility of oligooxyethylene linkages. In order to clarify the contributions of the two effects, a study was made of the photoreaction of similar compounds in which oxygen atoms are present only at the ends of the chain, and therefore only the electronic effects are involved. In these compounds, the quantum yields of the photocycloaddition were found to be low. Hence the high yields in the photocycloaddition of 3a-d are concluded to be ascribable to the flexibility of oligooxyethylene linkages.