实例四：如何实现下列转换 CH3 CH3 H H CH3 H CH3 CH3 H CH3 对 顺 CH3实例四：如何实现下列转换 CH3 CH3 H H CH3 CH3 H H CH3 CH3 H CH3 H H3C H CH3 H CH3 H H ？  对 h 顺