2- Heptulose, 1-deoxy-, preparation

Although these syntheses of deoxy ketoses have not been widely developed, the versatility of diazomethane as a synthetic reagent is amply demonstrated. In addition to heptuloses, the diazomethane method has been used for preparing various octuloses " and nonuloses. ... 

Azido-sugars are frequently prepared by reaction of epoxides with azide ion. 3-Azido-3-deoxy-L-threose 68 was synthesized from cu-but-2-ene-l,4-diol 66 via the Sharpless asymmetic epoxidation product 67, and was converted into 6-azido-6-deoxy-L-galocro-heptulose 69 by an enzyme-catalyzed aldol condensation (Scheme 13). 3-Azido-3-deoxy-L-etythrose, and thence 6-azido-6-deoxy-L-g/uco-heptulose were obtained in a similar way via 4-rerf-butyldiphenylsilyoxy-rraiu-but-2-enal. These and two other azido-heptulose isomers made from the enantiomeric 3-azido-3-deoxy-tetroses, were converted to a- and P-l-homonojirimycin and homomannonojirimycin on hydrogenation. Ethyl 3-azido-2,3-dideoxy-D-eryr/iro-pentopyranoside and its 3-C-methyl analogue 71, R=H or Me, were synthesized from crotonaldehyde or 3-methyl-2-... 

Standard procedures have been used to convert the 2,3-unsaturated heptonic acid (209) (prepared from 3,4,5,6,7-penta-0-acetyl-l-deoxy-I-diazo-D- / co-heptulose) into 5,6,7-tri-0-acetyl-2,3-dideoxy-D-nra6mo-heptofuranose (210),... 

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