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The structural assignment is based upon composition, infrared and nuclear magnetic resonance spectra.The infrared spectrum (carbon tetrachloride) of II had a band at 11.08 µ which is characteristic of the 6/3,-19-oxido bridge.1 The n.m.r. spectrum8 of the oxide lacked the C-19 methyl signal of starting t-steroid and was further characterized by the C-19 methylene multiplet centered at 6.23 r,9 Jab = 12 c.p.s., 5ab, 0.13 p.p.m. (2H); the unresolved C-6 multiplet at 6.68 r (1H); and the cyclopropyl C-4 methylene centered at 9.75 (2H).Treatment of 3a,5a-cycIo-6/3,19-oxidocholestane (II) with a trace of sulfuric acid in aqueous acetone for two hours yielded A5-choIestene-3/3,19-diol (II) in 80% yield. The identity of this material was proved by comparison with a known sample (melting point, mixture melting point, infrared) prepared by the method of Bowers.1 Experimental10 3a, 5a-Cyclo-6/3,19-oxidocholestane (II).-Lead tetraacetate 4.68 g. (0.107 mole) was recrystallized from benzene and dried in vacuo for 3 hr. It was dissolved in 250 ml. of dry benzene and 50 g. (0.5 mole) of anhydrous calcium carbonate was added.(5) M.

The structure of the adduct between maleic anhydride and triphenylphosphine has been determined by direct synthesis and spectral analysis. It is analogous to a phosphine methylene derivative (WITTIG reagent) stabilized by an u‐carbonyl group. With aldehydes, it gave none or very poor yields of the expected olefins; water (or alcohols) caused the anhydride ring to open, instead of forming triphenylphosphine oxide plus the corresponding hydrocarbon.

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