Phenyl methanoic acid

The carboxyl group withdraws electron density from the aromatic ring, which implies that the ring donates electrons to the carboxyl group as illustrated by structures 5 and 6 in Scheme 5.11. Such behaviour is acid weakening and benzoic acid (pKa 4.17) is weaker than formic acid (methanoic acid, HCO,H pKa 3.75). Note that electron donation by the phenyl group is apparently less than that of a methyl group, since acetic acid (ethanoic acid pKa 4.76) is a weaker acid than benzoic acid. 

Benzoic acid (benzene-methanoic acid, benzene-formic acid, benzene-carboxylic acid, phenyl-carboxylic acid, carboxy-benzene) [65-85-0]... 

Ethanoic acid Acetic acid Oxalic add / Phenyl methanoic add Benzoic add... 

In related syntheses of aminocyclopropylcarboxylic acids and acid derivatives, different combinations of protecting groups have been employed and among the compounds made were carnosadine (8), ( + )-2,3-methano-5-oxoproline (9), ( + )-2,3-methanoproline (10), /rani-l-benzoylamino-2-phenylcyclopropane-l-carboxylic acid (11) (and variants with substituted phenyl and thiophene) tra i-l-amino-2-isopropylcyclopropane-l-carboxylic acid (12) and coronamic acid (13). ... 

Cinnamyl methanoate Formic acid, cinnamyl ester 3-Phenylallyl methanoate 3-Phenyl-2-propen-1-yl formate... 

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