6. The unknown compound has molecular formula C2H10O2. In addition, its IR, 1H NMR, 13C NMR,
DEPT-90, DEPT-135 are listed below. Please answer the following questions:
【題組】
(A) How many 1° (CH3), 2°(CH2),3° (CH),4° (C) are there for the unknown respectively? (3 分)