label: (2R,4S)-2-methyltetrahydrofuran-2,3,3,4-tetrol(in) = (2R,4S)-2-methyltetrahydrofuran-2,3,3,4-tetrol(out)
label_lc: (2r,4s)-2-methyltetrahydrofuran-2,3,3,4-tetrol(in) = (2r,4s)-2-methyltetrahydrofuran-2,3,3,4-tetrol(out)