Synthesis of 11-oxatricyclo(6.2.1.0-üssü-2,7)undeca-2,4,6,9-tetraene derivatives and investigation of their chemical and photochemical reactions

9-Mono substituted oxabenzonorbornadiene derivatives 85, 90, 91, 95 were prepared starting from 9-bromo-l l-oxatricyclo[6.2.1.02'7]undeca-2,4,6,9-tetraene (81). " " ?> OCH, o=5~Br - ady- cooh- oi/1 90 COOCH ı CO,CH, 95 H 2 3 Reaction of 84 with suitable reagents afforded 9,10-disubstitued oxabenzonorbornadiene derivatives 96, 97, 98, 99, 100, 101, 102, 106. op o /r-C02CH3 84 Br 96 ^Br O 97 98 ^CH3 106^CH3 O n OH crftr- o^cr.+cöc;HcrM 99 CH> 100 C"3 101 C 3 102 \ CD2CH3 OCH3 The direct photolysis of methyl 10-methyl-ll-oxatricyclo[6.2.1.02'7]undeca-2,4,6,9- tetraene-9-carboxylate (100) formed methyl 1 -methyl- lH-indene-2-carboxylate (111) and meanwhile methyl 10-methyl-l l-oxatricyclo[6.2.1.027]undeca-2,4,6,9-tetraene-9- carbonitrile (106) afforded methyl 1 -methyl- lH-indene-2-carbonitrile (116) in the same manner. O ^1VC02CH3 hv_ CH3 100 o CN crfr 106 hy_ CH3