Isocyclics hexanes

A suspension of allyltriphenylphosphonium bromide in hexane treated with methyllithium in ether, the resulting soln. stirred 6 hrs. at room temp., ethyl a-isopropylideneacetoacetate dil. with hexane added dropwise at 5-10°, and allowed to stand 1 hr. at room temp. ethyl a-safranate. Y 69%. G. Biidii and H. Wuest, Helv. 54, 1767 (1971) cf. W. G. Dauben et al., Tetrah. Let. 1973, 4425 isocyclics with bridgehead double bonds s. Am. Soc. 95, 5088 (1973) Bredt s rule, review, cf. G. Kobrich, Ang. Ch. 85, 494 (1973). 

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