87, p. 325) synthesized it by acting with benzoyl chloride on zinc glycocollide.
The acid has been synthesized, as has also the inactive form of methylethylacetic acid; this modification is split into its optical antipodes by crystallization of its brucine salt.
Can also be synthesized by heating catechol with phthalic anhydride and sulphuric acid at 150 C. ' 'C 6 H4>Cg>O+C 6 H4(OH)2[1.2] = H 2 0 -}-C6H4C6H2(OH)2.
Also Marchlewski (in 1899) synthesized cane sugar from potassium fructosate and acetochloroglucose; and after Fischer discovered that acetochlorohexoses readily resulted from the interaction of the hexose penta-acetates and liquid hydrogen chloride, several others have been obtained.
In the preceding instances the carboxyl group has been synthesized or introduced into a molecule; we have now to consider syntheses from substances already containing carboxyl groups.