Proton N.M.R. spectra of 1-substituted benzocyclobutenes (Bicyclo[4,2,0]octa-1,3,5-trienes)

Abstract

The p.m.r. spectra of 15 1-substituted benzocyclobutenes (bicyclo[4,2,0]octa-1,3,5-trienes) were analysed. The effect of substituents on the N.M.R. parameters is discussed and compared with analogous effects in other systems, especially acenaphthene which is considered a relevant model. It is concluded that substituent effects in 1-substituted benzocyclobutenes are in no way exceptional, but they appear to be less quantitatively additive than in the acenaphthene system.