Identify the compound A (C5H10O) with the proton NMR spectrum shown. Compound A has IR absorptions at 3200-3600 cm-1 (strong, broad), 1676 cm-1 (weak), and 965 cm-1, and also has 13C NMR absorptions (attached protons in parentheses) at Δ 17.5 (3), Δ 23.3 (3), Δ 68.8 (1), Δ 125.5 (1), and Δ 135.5 (1).
