Ring contraction during the 6π-electrocyclisation of naphthopyran valence tautomers
作者:Christopher D. Gabbutt、B. Mark Heron、Suresh B. Kolla、Colin Kilner、Simon J. Coles、Peter N. Horton、Michael B. Hursthouse
DOI:10.1039/b807744d
日期:——
severe reaction conditions were required. The comparative ease of this rearrangement for the isomers and was rationalised on the basis of the relative isomer populations of the ring-opened naphthopyrans. The rearrangement of simple mono- and bis-methylsulfonylphenyl substituted photochromic naphthopyrans , was examined; the former failed to rearrange whereas the latter could be induced to rearrange only