The formation of 1,2-diphenylcyclobutane by the photocyclodimerization of styrene has opposing demands with regard to the styrene concentration: the first dimerization step with a short-lived active species needs high concentration of styrene, whereas the second cyclization step requires dilute conditions to avoid intermolecular side reactions. In order to overcome this monomer concentration effect
Intramolecular [2+2] Photocycloaddition. 15. Synthesis of 1,2-Ethano-9,10-methano[2.2]paracyclophanes
作者:Jun Nishimura、Yoichiro Horikoshi
DOI:10.1246/bcsj.65.941
日期:1992.3
The title compounds were prepared in 30% yield by the sequence of photocycloaddition of styrene derivatives, followed by bromination and elimination. The isomer raito of the products was 5 : 4.