“…Usov and Freimanis [269] prepared 3-aryl-3hydroxy -Ioxo -2 -phenyl -4 -phenylimino -1,2,3,4 -tetrahydroisoquinolines (80C) and showed that in polar solvents these compounds isomerize rapidly and irreversibly into isoindolinones (80B). Here ring contraction also takes place although the CONHR group adds to a C=N rather than to a carbonyl group.…”