Ethers isocyclics

As expected, heterocyclic enols and potential enols (i.e, compounds existing mainly in the CH form) behave toward diazomethane similarly to the open chain and isocyclic enols, i.e. they form enol methyl ethers by reactions of the SnI type (cf. footnote 29). Examples of this behavior are barbituric acid, picrolonic acid, dchydroacetic acid (64), 3-methyl-l-phenylpyrazolin-5-one, 1-phenylpyrazoli-dine-3,5-dione, 1,2-diphenylpyrazolidine-3,5-dionc, 3-hydroxy-... 

Matter, M. (1955) Polyethoxy ethers of isocyclic organic carboxylic acids. US Patent 2 714 608 (2 August 1955, to Ciba Pharmaceutical Products, Inc., Summit, N.J.). 

Further aldol condensation of the diketone 32 with methanolic KOH quantitatively gave the naphthalene 34, which was O-methylated to the dimethyl ether 74 (Scheme 15), the isocyclic molecular moiety of most of the Ancistrocladus and Triphyophyllum alkaloids (36,54,55). 

Diacoxy compds. from cyclic ethers with isocyclic skeletal rearrangement... 

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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