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Rhenium heptoxide, a known catalyst for hydrogenation of carboxylic acids to alcohols, forms synergistic combinations with palladium, platinum, rhodium and ruthenium catalysts. This effect is also seen at lower presures (500 psi). Synergism is also mainfest when rhenium and palladium (or rhodium) are used as supported catalysts on silica and used in a flow mode. An interaction of unknown nature between the metals suggests itself. The process is not very efficient at lower pressures giving lower conversion in the flow mode. At higher temperatures needed for higher rates, significant participation of side reactions such as decarboxylation of the acid and hydrogenolysis of the alcohol occurs yielding hydrocarbons. ABSTRACTBetulinol esters were prepared from stearic-, lauric-, palmitic-, oleic-and tall oil fatty acids via the acid-chloride and direct condensation routes. The degree of esterification was determined by high pressure liquid chromatography (HPLC), infrared (IR) and acid value measurements. The use of esters for air-dried, polyurethane and plastisol coatings was evaluated.

The rates of hydroxide decomposition of 1-benzyl-l-phenylphospholanium bromide (8), 1-benzyl-1-phenylphosphorinanium bromide (9), benzylethylmethylphenylphosphonium iodide (10) and seven substituted phosphetanium salts 1-7 have been measured in 1:1 ethanol-water at various temperatures. A marked rate enhancement was observed in going from the larger to the smaller rings; the rate of the acyclic salt 10 at 25°was comparable to the six-membered ring compound. Changes in both AH * and ASwere responsible for the rate variations; expected trends as well as apparent anomalies reflect the complexity of these overall, third-order reactions. Ring strain, the inductive effect of substituents on the ring and at phosphorus, and the degree of carbanion character adopted by the leaving group partially account for the observed activation parameters.