Stearolic acid, reaction

Sodium >-toluenesulfinate dihydrate, 34, 93 Sommelet reaction, 33, 93 Sorbic acid, 5-hydroxy-0-methyl, 5-lactone, 32, 57 Stannic chloride, 33, 91 Stearic acid, 34, 15 Stearolic acid, 37, 77 Stearone, 33, 84 cis-Stilbene, 33, 88 Irans-Stilbene, 33, 89... 

Reversing the order of addition, or using an ether as a solvent, causes a marked retardation of the reaction, with subsequent sudden, uncontrollable speed-up. Yields of about 80% are obtained and probably can be improved by devices to minimize the mechanical losses. 0 The addition of hydrogen fluoride to stearolic acid in methylene chloride solution to give 9,10-difluorostearic acid is cited in the patent literature.46 This claim should be verified, as either 9,9- or 10,10-difluoro-stearic acid or a mixture is much more likely to be the reaction product. 

The results of some oxidations with potassium permanganate differ depending on the pH of the reaction. For example, stearolic acid gives 9,10-diketostearic acid at pH 7-7.5 (achieved with carbon dioxide) and azelaic acid on treatment at pH 12 [864]. In some reactions, potassium permanganate is used as a catalyst for oxidation with other oxidants, such as sodium periodate. Thus alkenes are cleaved to carbonyl compounds or acids via vicinal diols obtained by hydroxylation with potassium permanganate, followed by cleavage by sodium periodate [763, 552]. 

Into a solution of 5.6 g (0.02 mol) of stearolic acid in 3 L of water containing 1.5 g (0.027 mol) of potassium hydroxide, carbon dioxide is introduced until pH 7.5 is reached. A solution of 6.3 g (0.04 mol) of potassium permanganate in 300 mL of water is added all at once. The temperature of the reaction mixture is kept at about 25 °C, and the pH is maintained between 7.0 and 7.5 by the gradual bubbling of carbon dioxide into the mixture as the oxidation proceeds. After 1 h, the excess of potassium permanganate is destroyed by the addition of sodium bisulfite, and hydrochloric acid is added to precipitate the product. 9,10-Diketo-stearic acid is filtered with suction and recrystallized from 200 mL of absolute ethanol at 0 °C. The total yield is 5.7-6.0 g (92-96%) of the product, mp 84.5-85.0 °C. 

Stearic anhydride, 1117 Stearolic acid, 603,946,1021,1036 Stearyl alcohol, 225 Stearyl bromid 657 Stephan reaction, 1116 Sterculic add, 1021-1022 Steroid acetonides, 801-802 Steroid diosphenols, 159-160 Stigmastadienone, 775-776, 889 Stigmasterol, 775-776, 889 CM-Stilbene, 156,967-968,975,1234 epoxide, 610,1192... 

Reaction with acetylenes. Sterculic acid was synthesized by refluxing stearolic acid in ether with methylene iodide and zinc-copper couple. Fractional crystallization... 

Reaction with acetylenes (1, 1021-1022). Gensler et at. as well as several other groups report that they were unable to. repeat the synthesis of sterculic acid by addition of methylene across the triple bond of stearolic acid. Gensler has effected the synthesis in about 30% overall yield by the following six-step route ... 

C-Labelled sterculic acid (151) has been synthesized by addition of diazo[2- ]-acetic ester to stearolic acid, followed by conventional reactions to remove the ester group. ° ... 

Decarbonylation of cyclopropene acids. In a study of the synthesis of methyl sterculate (6) from methyl stearolate (1), Gensler et al.1 were unable to repeat the apparently straightforward synthesis based on addition of the Simmons-Smith reagent described in 1, 1021-1022. They were also unable to eifect addition of methylene generated by cuprous bromide decomposition of diazomethane. However, the reaction of (1) with diazoacetic ester in the presence of copper bronze, followed by hydrolysis, gives the cyclopropene diacid (2) in 70-90% yield. 

The reaction of methyl stearolate (1) with diazoacetic ester in the presence of copper bronze produces a diester, which is hydrolyzed to the diacid (2). This is converted into the diacid chloride (3). Treatment with zinc chloride or other Lewis acid effects selective decarbonylation to give the cyclopropenium ion (4). Methanol is then added to convert the acid chloride grouping into the methyl ester (5). Finally reduction with sodium borohydride gives methyl sterculate (6). 

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