反应详情

The starting materials for said compounds 1, 2, 4, 6, 11 and 12 are the 3-carbomethoxy-2-methylpropanoyl chloride, 2-methylglutaric anhydride, 4-carbomethoxy-2-methylbutanoyl chloride, 3-methylglutaric anhydride and the erythro or threo 4-carbomethoxy-4-(2-phenethyl)-2-methylbutanoyl chloride respectively. That of compound 8 and 9 may be prepared as follows: The solution of 6.0 of meso-2,4-dimethylglutaric acid anhydride [J. Am. Chem. Soc. 77, 1862 (1955)] in 4 ml of methanol is refluxed for one hour and evaporated, to yield the erythro 4-carbomethoxy-2,4-dimethylbutanoic acid. It is converted into the acid chloride by refluxing it with 10.9 g of oxalyl chloride in 50 ml of methylene chloride for 2 hours, and evaporating said mixture.

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