This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: CHO H OH CH 2 OH H OH The configurational atom of a carbohydrate is the stereocenter farthest from the aldehyde. (the highest numbered stereocenter) In D-sugars this stereocenter is R, In L-sugars this stereocenter is S. D-erythrose L-erythrose D-threose L-threose Configurational atom CHO HO H CH 2 OH H OH CHO HO H CH 2 OH HO H CHO H OH CH 2 OH HO H D-aldotetroses L-aldotetroses NOTE: D and L sugars with the same name are ENANTIOMERS D-erythrose is 2R, 3R and L- erythrose is 2S, 3S (R) (R) (S) (S) Aldohexoses D-glucose L-glucose D-idose L-idose CHO H OH HO H H OH H OH CH 2 OH CHO HO H H OH HO H HO H CH 2 OH CHO HO H H OH HO H H OH CH 2 OH CHO H OH HO H H OH HO H CH 2 OH enantiomers C3-epimers Epimers: diastereomers with one unique stereocenter (all stereocenters are the same except one) D-allose CHO H OH H OH H OH H OH CH 2 OH enantiomers !-D-glucopyranose H OH HO H H OH H O CH 2 OH "-D-glucopyranose !# D-glucofuranose "-L-glucofuranose OH H H OH HO H H OH H O CH 2 OH H HO ! OH at anomeric carbon and oxygen attached to the configurational atom are on the same side in Fischer projection " OH at anomeric caron and oxygen attached to the configurational atom are on opposite sides in Fischer projection...
View Full Document
- Winter '07