Generation of the bicyclo[6,4,0]dodeca-4,9,11 -triene system from cis,cis-cyclo-octa-I .5-diene, using tetracyclone, 1,2,3.4-tetrachloro-5,5-dimethoxycyclopentad~ene, or a-pyrone. is followed by an intramolecular Diels-Alder reaction and results in the formation of tetracyclo [6,4.0,04~1a,0~~BJdodec-l O-enes. TETRAPHENYLCYCLOPENTADIENONE (tetracyclone) reacts slowly produced a hydrocarbon C,,H,, which was not with olefinic dienophiles to give, initially, carbonyl-the bicyclic triene (I; R = Ph), but the highly conbridged adducts, which by thermal elimination of carbon densed polycyclic compound (11; R = Ph), presumably rnon&ide afford products containing the cyclohexa-1,3-diene system*1 of cis,cis-cycIo-octa-l,5-diene at the reflux temperature 1 C. F. H.

The photoreactions of 1-and 2-naphthol, their trimethylsilyl (Me3Si) ethers, and 1 -methoxynaphthalene with acrylonitrile in a 1:1 isopropyl alcohol-tert-butyl alcohol mixture have been investigated. Irradiation of 2-naphthol and acrylonitrile gives 7-cyano-2,3-benzobicyclo[4.2.0]octa-2,4-dien-6-ol (3) while 2-naphthol trimethylsilyl ether gives the trimethylsilyl ether of 3. Base treatment of 3 or 5 trimethylsilyl ether gave l-(2-cyanoethyl)-2-naphthol. Photoaddition of 1-naphthol trimethylsilyl ether and acrylonitrile gives 8-cyano-2,3-benzobicyclo[4.2.0]octa-2,4-dien-l-ol trimethylsilyl ether, which is converted to the parent alcohol (6) by acid or to 2-(2-cyanoethyl)-

. LOCK. Can. J. Chem. 60, 1657Chem. 60, (1982.Irradiation of 2-cyanobicyclo[2.2. Ilhept-2-ene (2-cyanonorbornene, 4) in hexane, with the full arc of a mercury vapour lamp, gives the rearrangement products 1-cyanobicyclo[4.1 .O]hept-2-ene 5 and 7-cyanotricyclo[4. l.0.03.7]heptane 6 in the ratio 20: 1. These products were separated by preparative vpc. The structure of the major product 5 was determined by single crystal X-ray analysis. Reduction of 5 with lithium aluminum hydride gave the corresponding primary amine, which was converted to the p-bromobenzenesulfonamide 9, mp 150-15l0C, which gave single crystals from ethanol-water. The crystal and molecular structures are described. The minor product 6 was hydrogenated to give 7-cyanobicyclo[2.2. Ilheptane. Formation of 5 and 6 may involve concerted o,, + n,, and o,, + n,, processes respectively, which are photochemically allowed.

Addition of hexachlorocyclopentadiene or 1,2,3,4-tetrachloro-5.5-ethylenedioxycyclopentadiene to cyclo-octa-1,3,6-triene a t the 6,7-double bond is followed by an intramolecular diene addition, to give the pentacyclo-[5,5,1 ,02~6,03J0,04~8Jtridec-l 1 -ene system (I). However, attempts to obtain the more highly strained tetracyclo[4,4,0,02~9,05~8]dec-3-ene skeleton (VII) by an analogous intramolecular process failed.OUR interest in the dienophilic behaviour of cyclic polyenes 1-3 led us to examine that of cyclo-octa-1,3,6triene, obtained by partial reduction of cyclo-octatetraene with zinc in aqueous alcoholic sulphuric acid.* Treatment of the triene with hexachlorocyclopentadiene at ca. 100" for 24 hr. gave (in low yield) a high-melting 1 : 1 adduct, the i.r. spectrum of which showed no absorption in the region (near 1600 crn.-l) characteristic of ClC=CCl in a norbornene system; there was however a very weak C=C band at 1645 cm.-l. The n.m.r. spectrum (from 100 MHz spectrum; sweep-width 500 Hz)

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