Reduction acid derivatives

A few 6- and 8-cyanopurines have been prepared and undergo characteristic nitrile addition reactions rather readily. Thus, alkaline hydrolysis produces carboxamides, then carboxylic acids, alcoholysis leads to imidates, ammonolysis to amidines, hydrazinolysis to amidhydrazines, hydroxylamine to amidoximes, and hydrogen sulfide to thioamides. Acid hydrolysis tends to give the decarboxylated acid derivative. Reduction either by sodium-ethanol or, preferably, by catalytic hydrogenation affords aminoalkylpurines and addition of Grignard reagents produces, in the first place, acylpurines. As with aldehydes, most of the compounds examined have been relatively non-polar derivatives. Table 28 lists some reactions and relevant literature. 

Reduction-substitution of 2-alkynoic acid derivatives. Reduction of the triple bond of 2-alkynoic acid derivatives with functionalization at C-4 in the umpol-ung sense is effected by catalytic amounts of PhsP, HOAc, and a nucleophile. These processes involve 2,4-dienoic intermediates. 

Reduction of Carboxylic Acid Derivatives. Reduction of carboxylic esters has been enhanced with various activators. 

Perhaps the most common synthetic route to aminocyclohexane carboxylic acids is reduction of nitro- and amino-substituted benzoic acid derivatives. Reduction of (9rt/io-substituted acids give 7.706 reduction of meM-substituted acids give 7.104-, and reduction of pzira-substituted acids give 7.57102... 

Synthetic Transformation 24.1 Carboxylic Acid Derivatives—Reduction with Hydride... 

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