H3C 3C CH3 CH3 Hoc -OH CH3 CH3 H3 CH CH3 4=-c-地一一 OC2 H5 H3 CH3 CH3 CH2 CH3C Cl CH3 H3C CH3 C CH3 H3C CH3 C CH3 H3C CH3 O C OH CH3 H3C CH3 C CH3 H3C CH3 O C2H5 H C CH3 H3C CH3 OC2H5 H -H C CH3 H3C CH3 OC2H5 H3C C CH3 CH2 H -H H3C C CH3 CH2