HOCH2-CH(OH)-CH(OH)-CHO CHO CHO CHO CHO H OH HO S HO H H OH R R H- OH HO HS R H OH HO-H CH2OH CH2OH CH2OH CH2OH () (ii) (iii) (v) (2R,3R)-(-)赤藓糖(2S,3S-(+)-赤藓糖(2S,3R)-(+)-苏阿糖(2R,3S)-()苏阿糖 对映体，iiiv)对映体。 ((iii),①(v),(iii),(i(w)为非对映体。 CHO CH2OH OH OH H H R R CHO CH2OH H H HO HO S S CHO CH2OH HO H H OH S R CHO CH2OH H OH HO H S R (i) (ii) (iii) (iv) (2R,3R)-(-)-赤藓糖 (2S,3S)-(+)-赤藓糖 (2S,3R)-(+)-苏阿糖 (2R,3S)-(-)-苏阿糖 HOCH2 -CH(OH)-CH(OH)-CHO (i)(ii)对映体，(iii)(iv)对映体。 (i)(iii),(i)(v),(ii)(iii),(ii)(v)为非对映体