1-Naphthalenone, 1,2,3,4-tetrahydro

Photocyclisation of 8-alkoxy-l,2,3,4-tetrahydro-l-naphthalenones and 4-alkoxy-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ones gives naphtho[l, 8-bc]furans and cyclohepta[cd]benzofurans respectively, and conformational and substituent effects of 1,5-biradicals in the cyclisation process are discussed." " The same authors also describe substituent effects on the photocyclisation of ethyl 2-(8-oxo-5,6,7,8-tetrahydro-l-naphthyloxy)acetates and ethyl 2-(5-oxo-6,7,8,9-tet-rahydro-5H-benzocyclohepten-4-yloxy)acetates to give naphtho[l,8-bc]furans and cyclohepta[c,d]benzofurans respectively." Also reported are cyclisations involving photogenerated radical cations of unsaturated silyl enol ethers, fragmentation cyclisations of unsaturated ot-cyclopropyl ketones which occur by photoelectron transfer and give polycyclics, and kinetic and theoretical studies of [2+3] cycloadditions of nitrile ylids. These reactions have been studied mechanistically and their synthetic potential investigated. 

Reduction of quinones proceeds analogously to that of ketones. Whereas o-benzoquinone gives pyrocatechol smoothly, a mixture of 1,2-naphthalenediol and trans- 1,2-dihydro- 1,2-naphthalenediol is formed from 1,2-naphthoquin-one.360 3,4-Dihydro-4-hydroxy-l(2//)-naphthalenone is formed as well as 1,2,3,4-tetrahydro-l,4-naphthalenediol from 1,4-naphthoquinone.361... 

Tetr ydronaphthalene (tetralin) yields 1,2,3,4-tetrahydro-l-naphthol (1-tetrol) and 3,4-dihydro-l(2H)-naphthalenone (1-tetralone) as the major products and smaller amounts of 1-hydroperoxy-l,2,3,4-tetrahydronaphthalene We reasoned that copolymer latexes... 

C14H2 0O2 f 4a-Hydroxy-2,3,4aj3,8a/3-tetramethyl-4a, 5,8,8a-tetrahydro-1(4H)-naphthalenone, 46B, 144... 

A soln. of fra 5-4a,8-dimethyl-3-methoxy-5,6,7,8-tetrahydro-2(4aH)-naphthalenone in glacial acetic acid agitated with a Ng-stream and irradiated 3 hrs. with the Pyrex-filtered light of a 450 w. Hanovia lamp product. Y 89%. D. Caine et al., J. Org. Chem. 41, 1539 (1976). 

---