PHOTOCYCLIZATION REACTIONS .4. SYNTHESIS OF NAPHTHO1,8-BCFURANS AND CYCLOHEPTACDBENZOFURANS USING PHOTOCYCLIZATION OF ETHYL 2-(8-OXO-5,6,7,8-TETRAHYDRO-1-NAPHTHYLOXY)ACETATES AND ETHYL 2-(5-OXO-6,7,8,9-TETRHYDRO-5H-BENZOCYCLOHEPTEN-4-YLOXY)ACETAT

摘要

Photocyclization reactions were carried out on ethyl 2-(8-oxo-5,6,7, 8-tetrahydro-1-naphthyloxy) acetates 1a-e and ethyl 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzocyclohepten-4-yloxy)acetates 2a-e in acetonitrile. Irradiation of 1a-e gave naphtho1,8-bcfuranols 3a-e and naphtho1,8-bcfurans 4a-e in 33-83 yields and ethyl acrylates 5b-d were produced in 3-25 yields during irradiation of 1b-d. On the other hand, 2a-e afforded cycloheptacdbenzofuranols 6a-e and cycloheptacdbenzofurans 7a-e in 44-87 yields. Ethyl acrylates 8b-d were also produced in 7-43 yields from irradiation of 2b-d. Substituent effects on photocyclization and reaction pathways are discussed. References: 26