Abstract
Thermal [3,3] sigmatropic rearrangement of 6-cyclohex-2-enyloxy-1-methylquinolin-2(1H)-one (3) afforded 5-cyclohex-2-enyl-6-hydroxy-l-methyl-quinolin-2(1H)-one (4) in 86% yield. Compound 4 on treatment with pyridine hydrotribromide in CH2Cl2 gave exclusively non-bridged product 6 (85%) whereas compound 4 by a different route viz., acetylation followed by bromine addition and cyclization gave the bicyclic product 7 (80%). Compound 4 also furnished a bicyclic product 11 (80%) on treatment with cone. H2SO4.