preferred_name: (2R,4S)-2-methyl-2,4-dihydroxydihydrofuran-3-one => (S)-4,5-dihydroxypentane-2,3-dione
preferred_name_lc: (2r,4s)-2-methyl-2,4-dihydroxydihydrofuran-3-one => (s)-4,5-dihydroxypentane-2,3-dione
label: (2R,4S)-2-methyl-2,4-dihydroxydihydrofuran-3-one => (S)-4,5-dihydroxypentane-2,3-dione
label_lc: (2r,4s)-2-methyl-2,4-dihydroxydihydrofuran-3-one => (s)-4,5-dihydroxypentane-2,3-dione