5656-61-1Relevant academic research and scientific papers
Furan Derivatives. IV. On the Effects of Substituents in the Syntheses of 4,5-Dihydro-3H-naphthofurans
Horaguchi, Sakaaki,Hara, Mamoru,Suzuki, Tsuneo
, p. 865 - 869 (1982)
The reaction of (8-oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetic acids with acetic anhydride and sodium acetate give a mixture of 4,5-dihydro-3H-naphthofurans and lactones.The relative yiels of 4,5-dihydro-3H-naphthofurans and lactones varied according to kinds of substituents on the benzene ring of (8-oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetic acids.Substituents which make the methylene group approach closer to the carbonyl carbon atom of (8-oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetic acids by a steric effect seem to favor the production of 4,5-dihydro-3H-naphthofurans.On the other hand, substituents which make the methylene group separate from the carbonyl carbon atom seem to favor the production of lactones.An electron-withdrawing chlorine atom on the benzene ring of (8-oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetic acids also favors the production of 4,5-dihydro-3H-naphthofurans.
Photocyclization Reactions. Part 3 [1]. Synthesis of Naphtho[1,8-bc]-furans and Cyclohepta[cd]benzofurans Using Photocyclization of 8-Alkoxy-1,2,3,4-tetrahydro-1-naphthalenones and 4-Alkoxy-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ones
Sharshira, Essam Mohamed,Iwanami, Haruki,Okamura, Mutsuo,Hasegawa, Eietsu,Horaguchi, Takaaki
, p. 17 - 25 (2007/10/03)
Photocyclization reactions were carried out on 8-alkoxy-1,2,3,4-tetrahydro-1-naphthalenones (six-membered ring ketones) 4a-g and 4-alkoxy-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ones (seven-membered ring ketones) 5a-e in acetonitrile. Irradiation of 4a-f gave rearranged naphthyl alcohols 8a-f as major products. In the case of 4g, 2a,3,4,5-tetrahydronaphtho[1,8-bc]furan-2a-ol 6g was obtained. In contrast, irradiation of 5a-e afforded 2,2a,3,4,5,6-hexahydrocyclohepta[cd]benzofuran-2a-ols 9a-e in good yields. The difference in reactivities between 4a-g and 5a-e is attributed to the conformation of six- and seven-membered rings. Conformational and substituent effects in cyclization step of 1,5-biradicals are discussed along with reaction pathways.
Photocyclization Reactions. Part 4 [1]. Synthesis of Naphtho[1,8-bc]-furans and Cyclohepta[cd]benzofurans Using Photocyclization of Ethyl 2-(8-Oxo-5,6,7,8-tetrahydro-1-naphthyloxy)acetates and Ethyl 2-(5-Oxo-6,7,8,9-tetrahydro-5H-benzocyclohepten-4-yloxy)acetates
Sharshira, Essam Mohamed,Iwanami, Haruki,Okamura, Mutsuo,Hasegawa, Eietsu,Horaguchi, Takaaki
, p. 137 - 144 (2007/10/03)
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 naphtho[1,8-bc]furanols 3a-e and naphtho[1,8-bc]furans 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 cyclohepta[cd]benzofuranols 6a-e and cyclohepta[cd]benzofurans 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.
Conformational Effects in Photocyclization of Six and Seven-membered Ring Alkoxyketones
Horaguchi, Takaaki,Iwanami, Haruki,Tanaka, Takakazu,Hasegawa, Eietsu,Shimizu, Takahachi
, p. 44 - 46 (2007/10/02)
Irradiation of 8-alkoxytetrahydro-1-naphthalenones 5 gave rearranged naphthyl alcohols 11 as major products and in contrast, 4-alkoxytetrahydrobenzocyclohepten-5-ones 6 afforded tetrahydrocycloheptabenzofurans 14 in good yields; the difference in reactivities is attributed to the conformation of six- and seven-membered rings.
