Selectivity of the generation of 3- and 4-carboxyalkyl radicals from substituted glutaric and adipic acids and their oxidative lactonization

TLDR: The selectivity of the oxidative decarboxylation of acids with carboxyl groups at secondary and tertiary C atoms under the action of the S2O82−--Ag+ and S 2O82 −-Ag +- Cu2+ systems is at least an order of magnitude faster than that of acids having COOH groups at a primary C atom, as a result of which 3 and 4-carboxyalkyl radicals with the general formula R'RĊ(CH2)nCOOH (R is alkyl or

Abstract: 1. The oxidative decarboxylation of acids with carboxyl groups at secondary and tertiary C atoms under the action of the S2O82−- Ag+ and S2O82−-Ag+- Cu2+ systems is at least an order of magnitude faster than that of acids with COOH groups at a primary C atom, as a result of which 3- and 4-carboxyalkyl radicals with the general formula R'RĊ(CH2)nCOOH (R is alkyl or phenyl, R′ is H or alkyl, n=2 or 3) are generated with > 90% selectivity from 2-substituted glutaric and adipic acids. 2. The 3- and 4-carboxyalkyl radicals are completely or partially converted under their generation conditions into lactones. The selectivity of the oxidative lactonization increases from 0.30 to 0.97 along the series of radicals C2H5ĊH(CH2)3COOH, C2H5ĊH(CH2)2COOH, ĊH2(CH2)3COOH, ĊH2(CH2)2COOH, (CH3)2Ċ(CH2)2-COOH, and C2H5ĊH(CH2)2COOH in the case of the S2O82−-Ag+ system and from 0.72 to 1 along this series in the case of the S2O82−- Ag+- Cu2+ system.