These two classification are frequently combined. For example C4 aldose→- aldotetr (丁醛糖) Cs ketose ketopentose (戊酮糖) CH,OH CH,OH CH CH C=0 CHOH CHOH (CHOh)n (CHOH)n CHOH CHOH CH,OH CH,OH CH,OH CH,OH An aldose a ketose aldotetrose ketopentose (醛醣) (酮糖) (丁醛糖) (戊酮糖)
These two classification are frequently combined. For example: C4 aldose aldotetrose (丁醛糖） C5 ketose ketopentose (戊酮糖） O CH CHOH CHOH CH2OH O CH (CHOH)n CH2 OH CH2 OH C (CHOH)n O CH2 OH CH2 OH C O CHOH CHOH CH2 OH An aldose (醛醣) A ketose (酮糖） aldotetrose (丁醛糖） ketopentose (戊酮糖）
22.2B D ANDL DESIGNATIONS OF MONOSACCHARIDES Glyceraldehyde exists two enantiomeric forms which have the absolute configurations H C—H HDC-OH lOrCH CH,OH CH,OH (+)-Glyceraldehyde ()-Glyceraldehyde (+)-甘油醛 ()+甘油醛 (+)-Glyceral dehyde should be designated(R)-(+)-Glyceraldehyde and(-)-Glyceraldehyde should be designated(S)-(-Glyceraldehyde (section 5.5)
22.2B D AND L DESIGNATIONS OF MONOSACCHARIDES Glyceraldehyde exists two enantiomeric forms which have the absolute configurations: O C C CH2OH H OH H O C C CH2 OH HO H H (+)-Glyceraldehyde (+)-甘油醛 (-)-Glyceraldehyde (-)-甘油醛 (+)-Glyceraldehyde should be designated (R)-(+)- Glyceraldehyde and (-)-Glyceraldehyde should be designated (S)-(-)- Glyceraldehyde (section 5.5)
Other system designated (+)-Glyceraldehyde as D-(+)-Glyceraldehyde and (-)-Glyceral dehyde as L-(-)-Glyceraldehyde I CH,OH I CHO O 2* CHOH 3* CHOH 3*CHOH 4* CHOH HDC-OH HOrC-H 5 CH,OH Highest number sterocenter CH,OH D-aldopentose L-ketohexose (D-戊醛糖) (L-已酮糖) D and l designations are not necessarily related to the optical rotations of the sugars to which they are applied
Other system designated (+)-Glyceraldehyde as D-(+)- Glyceraldehyde and (-)-Glyceraldehyde as L-(-)-Glyceraldehyde. CHO CHOH CHOH C CH2 OH C CHOH CHOH C CH2OH H OH HO H * * * * O CH2OH Highest number sterocenter 1 2 3 4 5 1 2 3 4 D-aldopentose (D-戊醛糖） L-ketohexose (L-己酮糖） D and L designations are not necessarily related to the optical rotations of the sugars to which they are applied
22.2C ATRUCTURAL FORMULAS FOR MONOSACCHARIDES Fisher projection formula: horizontal lines project out towards the reader and vertical lines project behind the plane of the page CHO H人OH CHO CHO H OH HOH HCOH 0-TH HOH≡三 HOtCH H OH HeCOH H OH HOOH HDCKOH CH,OH CH,OH CHOH Fisher projection Cirele-and-line Wedge-line-dashed formula formula wedge formula 3
22.2C ATRUCTURAL FORMULAS FOR MONOSACCHARIDES Fisher projection formula: horizontal lines project out towards the reader and vertical lines project behind the plane of the page. CHO H OH HO H H OH H OH CH2OH CHO H C OH C C HO H C H OH H OH CH2 OH CHO HO H H OH H OH H OH CH2OH Fisher projection formula Cirele-and-line formula Wedge-line-dashed wedge formula 1 2 3
CHOH CHOH O、OH H OH H OH H OH OH H H H Haworth formulas 5 OH OH H2C HC HO HO HO OH OH OH OH a-D-(+)-Glucopyranose B-D-(+)-Glucopyranose (α-D-(+)-吡喃(型)葡萄糖) (βD-(+)-吡喃(型)葡萄糖) Open-chair structure(1, 2, or 3)exists equilibrium with two cyclic forms 4 and 5 or 6 and 7
Open –chair structure (1, 2, or 3) exists equilibrium with two cyclic forms 4 and 5 or 6 and 7. H O OH H OH H H OH OH CH2OH H H O OH OH H H H OH OH CH2OH H 4 5 6 7 Haworth formulas + + O HO HO H2C OH OH OH O HO HO H2 C OH OH OH α-D-(+)-Glucopyranose (α-D-(+)-吡喃(型)葡萄糖) β-D-(+)-Glucopyranose (β-D-(+)-吡喃(型)葡萄糖)