The mechanism of the oxidation of alcohols by silver carbonate on Celite was thoroughly investigated to ascertain the nature of the transition state and the possible intervention of reaction intermediates. Kinetic, stereochemical, and isotopic labeling techniques were used to differentiate among the various theoretically plausible mechanistic alternatives. The effects of surface adsorption and solvent composition on the outcome of the reaction were also studied. The data were consistent with a concerted process for which a model is proposed.

A convenient scheme for the stepwise degradation of ethyl caprinate (1) is described, which allows the removal of either one, two, or three carbon fragments from the chain, affording high yields of the corresponding carbonyl compounds. The method may have important applications in the transformations of steroids, lipids, and other natural products.

Chromatography of the residue on alumina, activity IV, and elution with benzene gave 40 mg of oily 12: ir (CC14) NH 3.18 (m), C=0 6.00 (s), C=C 6.32 µ (s). In view of its instability, it was used for the next reaction without further purification.A solution of 40 mg of 12 in 10 ml of 10% methanolic potassium hydroxide was stirred at room temperature under nitrogen for SO hr. It was neutralized with 10% hydrochloric acid and evaporated. Extraction of the residue with ethanol and evaporation of the extract gave lOmg of a viscous oil which crystallized slowly. Crystallization from ethyl acetate-ethanol yielded 4 mg of prisms of dZ-18,19-dihydroantirhine (5): mp 95-97.5°; infrared, ultraviolet, mass spectral, and tic characteristics identical with those of an authentic sample;6•18 m/e 298.204516 (caled 298.204503).Methyl Demethylilludinate ( 14).-A solution of dry potassium ¿erí-butoxide (from 620 mg of potassium) and 3.24 g of diester 7c in 25 ml oí 1,2-dimethoxyethane was added dropwise to 1.75 g of 3,3-dimethylcyclopentanone16 over a 1-hr period and the mixture was stirred at room temperature under nitrogen for 15 hr. Hydrochloric acid (50 ml of 3 N) was added and the mixture was evaporated at 50°to dryness. The residue was dried further in a vacuum desiccator for 12 hr and then dissolved in 50 ml of methanol saturated with hydrogen chloride gas. After

A novel method for the direct conversion of some substituted ethylenes to ketones is described. The ketone synthesis is shown to proceed with a concurrent rearrangement of the carbon skeleton. A mechanism, supported by isotopic labeling experiments, is postulated to account for the transformation.The addition of bromine to olefins is a well-known reaction frequently used as a qualitative test for unsaturation.The products of such additions are usually the corresponding dibromides. However, in at least two reported4•5 instances ketones have been isolated as by-products.

Trimethyl-1,2,2-triphenylethylammonium-l-C14 hydroxide (XI, 0.737 mc./mole) was synthesized and pyrolyzed under the conditions of the Hofmann elimination, affording triphenylethylene-C1' as the sole product. Oxidative degradation of the latter, followed by radioactivity assay of the fragments, disclosed that virtually all of the label resided in the benzoic acid (a-C) fragment, and that less than 0.4% was present in the benzophenone (&C) fragment. Thus, the pyrolysis of X I occurred without significant skeletal rearrangement. In view of the extreme ease with which the 1,2,2-triphenylethyl carbonium ion has been shown previously in other reactions to suffer rearrangement, we exclude the mechanistic involvement of such an intermediate, either of the classical or nonclassical type, in the present elimination. The results are consistent, however, with a synchronous E2 or an Elcb mechanism.

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Caprinsäureäthylester (I) liefert mit Phenylmagnesiumbromid das Carbinol (II), das zum 1,1‐Diphenyl‐1‐decen (III) dehydratisiert wird.

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