Compound A undergoes hydrolysis of its acetal function in dilute sulfuric acid to yield 1,2- ethanediol and compound B (C6H6O2), mp 54°C. Compound B exhibits a carbonyl stretching band in the infrared at 1690 cm-1 and has two singlets in its 1H NMR spectrum, at δ 2.9 and 6.7 ppm, in the ratio 2:1. On standing in water or ethanol, compound B is converted cleanly to an isomeric substance, compound C, mp 172-173°C. Compound C has no peaks attributable to carbonyl groups in its infrared spectrum. Identify compounds B and C.