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Addition of Cyclohep tatrienylidene to cis- and trans- 1,3-Pentadiene and to Styrene. Rearrangement of Spiro[2 .6]nona-4,6,8-trienes1 Edward E. Waali and W.M.Jones" Contribution from the Department of Chemistry, University of Florida, Gainesville, Florida 32601. Receicied May 15, 1973 Abstract: Cycloheptatrienylidene (1) adds to the terminal double bond of cis- and trans-l,3-pentadiene. The rearranges above 50" to yield the geometric adduct from the cis diene, l-cis-propenylspiro[2.6]nona-4,6,8-triene, isomers of 8-methylbicyclo[5.4.0]undeca-l,3,5,9-tetraene(3a and 3b). l-trans-Propenylspiro[2.6]nona-4,6,8-triene is unstable at room temperature and also rearranges to 3a and 3b, although giving different relative amounts. The carbene, 1, also adds to the vinyl group of styrene to yield l-phenyIspiro[2.6]nona-4,6,8-triene.At 75",it rearranges to 8-phenylbicyclo[5.2.O]nona-l,3,5-triene. At temperatures above 135", this bicyclic triene yields 2-phenylindan. The carbene additions are consistent with a nucleophilic attack by 1. Stepwise, diradical processes are suggested for the rearrangement of the spiro[2.6]nonatrienes.
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ne of the atypical chemical properties of carbocyclic aromatic carbenes such as diphenylcyclopropenylidene and cycloheptatrienylidene (1)is their reluctance t o add t o simple olefins. For example, the
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0 generation of cycloheptatrienylidene in the presence of cyclohexene, tetramethylethylene, or even norbornene gives no trace of adduct, the only product being the carbene dimer, heptafulvalene.2 In fact, t o date both diphenylcyclopropenylidene and 1 have been found t o add only to double bonds substituted with strongly electron-withdrawing groups. At this time we would like t o report the addition of 1 t o cis- and trans-1,3-pentadiene and styrene and the thermal rearrangements of the resulting spirononatrienes, one of which occurs at room t e m p e r a l ~ r e . ~
Results Cycloheptatrienylidene (l),generated by both thermolysis and photolysis of the sodium salt of tropone tosylhydrazone (2), added in reasonable yield to both cis- and trans-l,3-pentadiene. For example, slow addition of 2.8 mmol of the salt to a solution of 35 inmol of trans-1,3-pentadiene in 20 ml of diglyme at 100" gave 5 % heptafulvalene and 4 1 x of a mixture of the geometric isomers of 8-n~ethylbicyclo[5.4.O]undeca-l,3,5,9tetraene, 3a and 3b, in the ratio 88:12. Under the same conditions, the cis diene gave the same products although in different relative amounts, 3a:3b = 61 :39. Although the two adducts could not be separated by solution chromatography (tlc or column) and were unstable to preparative glpc conditions, it was possible by comparing the nmr spectrum of the product mixture
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(1969). (3) W. M. Jones, M. E. Stowe, E. E. Wells, Jr., and E. W. Lester, ibid., 90, 1849 (1968). (4) Dr. I
