
TY  - JOUR
A1  - Au-Yeung, BW 
A1  - Chan, T 
A1  - Tam, SW 
T1  - Synthesis and P.M.R. study of 2-(2',4'-Dihydroxy-6'-methylbenzoyl)-3,6-dihydroxybenzoic acid and its methyl ethers
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1975
VL  - 28
IS  - 3
SP  - 657
EP  - 663
KW  - 
UR  - https://doi.org/10.1071/CH9750657 
N2  - The syntheses of 2-(2?,4?-dihydroxy-6?-methylbenzoyl)-3,6- dihydroxybenzoic acid (4) and its methyl ethers are described. Treatment of 6-hydroxy-2-(2?-hydroxy-4?-methoxy-6?-methylbenzoyl)-3- methoxybenzoic acid (8) with alcoholic potassium hydroxide gave 2- hydroxy-6-methoxy-8-methyl-9-oxoxanthene-1-carboxylic acid (9). Comparison of the p.m.r. spectra of these structurally related 2- benzoylbenzoic acids revealed that the chemical shifts of the aryl methyl and the ring protons are significantly influenced by the existence of intramolecular hydrogen bonding. 
ER  -

