_d_-Gulose _l_-Gulose _d_-Idose _l_-Idose CH_{2}OH CH_{2}OH CH_{2}OH CH_{2}OH | | | | HO-C-H H-C-OH HO-C-H H-C-OH | | | | H-C-OH HO-C-H H-C-OH HO-C-H | | | | HO-C-H H-C-OH HO-C-H H-C-OH | | | | HO-C-H H-C-OH H-C-OH HO-C-H | | | | CHO CHO CHO CHO _d_-Altrose _l_-Altrose _d_-Allose _l_-Allose (unknown) (unknown) CH_{2}OH CH_{2}OH CH_{2}OH CH_{2}OH | | | | H-C-OH HO-C-H H-C-OH HO-C-H | | | | HO-C-H H-C-OH H-C-OH HO-C-H | | | | HO-C-H H-C-OH H-C-OH HO-C-H | | | | HO-C-H H-C-OH H-C-OH HO-C-H | | | | CHO CHO CHO CHO 2. Aldohexoses of the dulcitol series: _d_-Galactose _l_-Galactose _d_-Talose _l_-Talose CH_{2}OH CH_{2}OH CH_{2}OH CH_{2}OH | | | | H-C-OH HO-C-H H-C-OH HO-C-H | | | | HO-C-H H-C-OH HO-C-H H-C-OH | | | | HO-C-H H-C-OH HO-C-H H-C-OH | | | | H-C-OH HO-C-H HO-C-H H-C-OH | | | | CHO CHO CHO CHO 3. Ketohexoses: