Activated anhydrides of tartaric and malic acids

Tartaric acid and its acyl derivatives. Part 5. Direct synthesis of monoacyltartaric acids and novel mono(benzoyl)tartaric anhydride: unusual findings in tartaric acid acylation

“…It was found that the product of di-acylation, acid 3a, occurs together with the monoacylated anhydride 7a, which shows that acylation of tartaric acid 1 proceeds via two routes (Scheme 2). The formation of tartaric anhydride itself in the first step is not to be excluded, but neither we nor other authors 12,36 were able to isolate it or synthesize until now.…”

“…Due to their historical application, the synthesis of acids 3 is well known and described. 11,12 They are obtained by exhaustive acylation of tartaric acid 1 to the corresponding diacyltartaric anhydrides 4, which is followed by hydrolysis. 13 According to this procedure, acids 3 are prepared in high yield both in academic and industrial laboratories.…”

Parallel Synthesis and Yeast Growth Inhibition Screening of Succinamic Acid Libraries

“…This modified protocol was successfully applied to the production of libraries 1 − 8 . Model experiments with anhydride 5 and amines 14 , 16 , 19 , and 21 (see Experimental Section) showed the regioselective formation of the expected adducts, resulting from amine attack upon the more reactive electron-deficient C1-carbonyl. , However, minor amounts of regioisomeric adducts arising from attack to the less reactive C4-carbonyl were also observed ( 1 H NMR and or HPLC analysis) under our optimized reaction conditions…”

“…Model experiments with anhydride 5 and amines 14, 16, 19, and 21 (see Experimental Section) showed the regioselective formation of the expected adducts, resulting from amine attack upon the more reactive electron-deficient C1-carbonyl. 18,19 How- ever, minor amounts of regioisomeric adducts arising from attack to the less reactive C4-carbonyl were also observed ( 1 H NMR and or HPLC analysis) under our optimized reaction conditions. 20 Libraries 1-5 were duplicated, and one set was submitted to acetate cleavage in the presence of NaOMe/MeOH, followed by quenching with excess Amberlyst15 as a proton source to give libraries 9-13.…”

Regioselective Ring Opening of Malic Acid Anhydrides by Carbon Nucleophiles. Application in the Synthesis of Chiral Tetronic Acids

“…The O-protected hydroxysuccinic anhydrides ( I ) derived from malic acid offer a unique way to achieve both these tasks. These anhydrides react regioselectively at the C-2 site with oxygen and nitrogen nucleophiles providing malic acid monoesters and monoamides, respectively. However, no report has appeared concerning similar behavior toward carbon nucleophiles.…”