Compound A has the molecular formula C6H12O3 and shows a strong IR absorption peak at 1710 cm-1. When treated with iodine in aqueous sodium hydroxide, A gives a yellow precipitate. When A is treated with Tollens' reagent (a test for an aldehyde or a group that can be hydrolyzed to an aldehyde), no reaction occurs; however, if A is treated first with water containing a drop of sulfuric acid and then with Tollens' reagent, a silver mirror (positive Tollens' test) forms in the test tube. Compound A shows the following 1H NMR spectrum:
Singlet .................................. δ 2.1
Doublet ................................. δ 2.6
Singlet ................................... δ 3.2 (6H)
Triplet ................................... δ 4.7
Write a structure for A.