IV v of the carboxyl group. The series of reactions is shown (IX-XV). The structure of~~:~~ 0 c H 3+:: lzpooH+~ z~ cooH compound XI had been established previously with~ ertainty,~ thus fixing the position of the carboxyl group in compound VIII. The dimethyl ether (VIII), mp 115', obtained by the two methods just described as an intermediate in the synthesis of the dihydroxymonocarboxylic acid (I) proved not to be
