Manno-1-deoxynojirimycin

Johnson, C R, Golebiowski, A, Schoffers, E, Sundram, H, Braun, M P, Chemoenzymatic synthesis of azasugars D-talo- and D-manno-l-deoxynojirimycin, Synlett, 313-314, 1995. 

A chemoenzymatic synthesis of 1-deoxynojirimycin (2) was started by the condensation of DHAP and 3-azido-2-hydroxypropanal (104) catalyzed by the enzyme FDP aldolase to give 105 and 106 (Scheme 20). " Removal of the phosphate was catalyzed by phosphatase, followed by hydrogenation of the mixture over palladium on carbon to give a 4 1 mixture of 2 and its manno analogue. 

An improved, three-step synthesis of iV-butyl-l-deoxynojiromycin from D-glucose has been described, involving an enzymic oxidation ofN-butylglucamine. A synthesis ofA/ -[ C]methyl-1-deoxynojirimycin and its manno epimer has been reported in a study of glycosidase inhibition. l,3,4-Trideoxy-3-fluoronojirimycin and its manno epimer have been characterized and stereochemically distinguished by mass-analyzed ion kinetic energy spectroscopy. ... 

A detailed n.m.r. study of the a-glucosidase inhibitor 1,5-dideoxy-1,5-methylimino-D-glucitol (H-methyl-l-deoxynojirimycin) has been undertaken. It was observed that in acidic DaO the two isomers (6a) and (6b) with an equatorial or axial H-methyl group respectively, are present in 11 1 ratio, and that the predominant (>90%) rotamer state about the C-5 - C-6 bond, both in the cationic diastereomer (6a) and in the free base is aauche-gausiie- The "-H- and - C- n.m.r. parameters of racemic a- and fi-Dseudo-aluco-. pseudo-qalacto-. and pseudo-manno-pvranose have been reported, and the fully assigned and n.m.r. 

Borohydride reduction of 2-amino-2-deoxy-D-manno- and -D-gluco-furanurono-3>6-lactones gave the 1-deoxynoJirimycin analogues (63) and (64) respectively in good yield.The dissociation of the nojirimycin-bisulphite adduct has been examined and the cyclic structure (65) suggested. The anomeric effect in nojirimycin is referred to in Chapter 20. 

---