千HCI OH 千HCI OR' RCHO R'OH RCHOR' RCHOR' 半缩醛 R'OH 缩醛 CH2-CH2 H2C— CH2 H3C一CH →CH0 H3C-CH CH-OH OH 0 OH CH2 H2- CH2—CH CH2 CH2-CH20H CH2-CH2
CH2 CH CH2 CHO H3C OH H2C CH2 CH O H CH 3C OH CH2OH CH2 CHO CH2 CH2 CH2 CH CH2 CH2 CH2 O OH RCHO + R’OH 干HCl RCHOR’ OH 干HCl RCHOR’ OR’ 半缩醛 缩醛 R’OH
单糖的环式结构与变旋光现象 HO-C-H CHO H-C-OH H- H H- HO- H HO H H0- H OH H OH H 0- H- H 0- CH20H CH20H CH20H B一D-(+)一吡喃葡萄糖 D-葡萄糖 a-D-(+)-吡喃葡萄糖 63.6% 极少量 36.4% [a]b=+18.7° [a]D=+112° CH20H [a]D=+52.7° CH20H 0 H 0 H OH 哈沃斯式 OH H HO HO OH OH OH BD-(十)吡喃葡萄糖 aD-(十)吡喃葡萄糖
β-D-（+）-吡喃葡萄糖 α-D-（+）-吡喃葡萄糖 HO OH HO OH OH CH2OH O H H HO C H H H CH2OH O H H CHO H C OH CH2OH H OH OH H H H H OH H OH HO D-葡萄糖 投影式 [α]D= + 18.7° [α]D= + 112° 63.6％ 极少量 36.4％ [α]D= + 52.7° 单糖的环式结构与变旋光现象 O OH OH HO H H H H OH CH2OH H O OH OH HO H H H H CH2OH OH H α-D-(＋)-吡喃葡萄糖 哈沃斯式 β-D-(＋)-吡喃葡萄糖
1CHO 2 HH OH H 6 CH2OH H 4 3 1 从 HOCH2 CHO H 0 OH H OHOH H OH H 6 CH20H OH H B-型 HO H H H OH 6 CH2OH 5 H CH20H H OH CH2OH OH CHO H 0 H OH H HO OH H HO a-型 2 OH HO OH H OH OH H OH
CHO OH HO CH2OH OH OH H H H H HOCH2 CHO OH OH OHOH H H H H HO CHO OH OH OH CH2OH H H H H HO CHO OH OH OH CH2OH H H H H HO OH OH OH O CH2OH H H H H H HO OH OH O CH2OH H H H H OH H α-型 6 β-型 1 2 3 4 5 1 3 2 4 5 6 1 5 234 6
CH2OH CH2OH CH2 OH H 0 H OH H OH 简写为 OH αD-(+)-吡喃葡萄糖 HO OH HO OH HO OH H OH OH OH CH2OH CH2OH CH2OH 0 OH H O OH OOH HO H OH 简写为 OH BD-(十)吡喃葡萄糖 HO HO H OH OH OH C,的差向异构体又互称为端基异构体或异头物，半缩 醛碳也叫异头碳
C1的差向异构体又互称为端基异构体或异头物，半缩 醛碳也叫异头碳。 HO OH OH O CH2OH H H H H OH H HO OH OH OH O CH2OH H H H H H β-D-(＋)-吡喃葡萄糖 α-D-(＋)-吡喃葡萄糖
CH2OH H CH2OH H H2OH 0 OH H H H -0 O OH H H HO OH HO H OH OH OH a-D(十)-吡喃葡萄糖 N式 A式 CH2OH H/ 0 CH2OH OH OH CH2OH H 0 OH H H HO O -0 H H OH H HO H H H O OH BD-(十)吡喃葡萄糖 N式 A式 稳定性：B-D-(+)吡喃葡萄糖>α-D-(十)吡喃葡萄糖
HO OH OH OH O CH2OH H H H H H HO OH OH O CH2OH H H H H OH H β-D-(＋)-吡喃葡萄糖 O α-D-(＋)-吡喃葡萄糖 HO HO CH2OH OH HO H H H H O OH OH OH CH2OH OH H H H H H O HO HO CH2OH OH HO H H H H O OH OH OH OH CH2OH H H H H H N式 A式 β-D-(＋)-吡喃葡萄糖 N式 A式 稳定性：β-D-(＋)-吡喃葡萄糖 > α-D-(＋)-吡喃葡萄糖