Synthesis from D-galactose

1 Synthesis from o-galactose (-)-Anisomycin (1) has been synthesized from D-galactose by conversion firstly to ethyl 2,3-di-0-benzyl-(3-D-galactofuranoside 

---

Synthesis from D-galactose The (3-lactam isomers 17 and 18 have been prepared-from the D-galactose derivative 16 (Scheme 2). Isomerization of 16 with NaHCOs followed by treatment with sodium metaperiodate and then reduction afforded 17. On the... 

Micheel then slightly modified his synthesis, starting from D-galactose diethyl dithioacetal (19) (Scheme 2).33 Selective tritylation of the 6-hydroxyl group followed... 

A further synthesis of phytosphingosine (11) was achieved [37] from D-galactose via 3,4,6-tri-O-benzyl-D-galactose. Reduction of the latter and subsequent acetonation gave the galactitol derivative (7), and this on mesylation and reaction with potassium... 

A synthesis of D-tagatose from D-galactose proceeds via the hexos-2-ulose derivative 212, which was obtained by oxidation under Moffatt conditions from 211 and exists as the tautomeric form 213.426... 

O. Moradei, C. du Mortier, A. Fernandez Cirelli, and J. Thiem, Simple stereocontrolled synthesis of methyl 2-deoxy-D-mv/ ro-hexopyranosid-4-uloscs, Thomboxane B2 (TXB2) precursor, from D-galactose,. /. Carbohydr. Chem., 14 (1995) 525-532. 

Synthesis of Ascorbic acid and of Disaccharides (i) The synthesis of Vitamin C (75), ascorbic acid from D-galactose (ref.72) and that from D-glucose (ref.73) were described in the same year which also saw the development of the the latter as an industrial route. Sorbitol obtained by the reduction of D-glucose was oxidised with the bacterium Acetobacter suboxvdans to L-sorbose which as the bis-acetonylidene derivative was next oxidised to the corresponding acid, L-2-oxogulonic acid, the methyl ester of which was base-catalysed to afford the final product as illustrated. 

Dubreuil, D., Cleophax, J., De Almeida, M. V., Verre-Sebrie, C., Liaigre, J., Vass, G., Gero, S. D. Stereoselective synthesis of 6-deoxy and 3,6-dideoxy-D-myoinositol precursors of deoxy myoinositol phosphate analogs from D-galactose. Tetrahedron 1997, 53,16747-16766. Paquette, L. A., Kinney, M. J., Dullweber, U. Practical Synthesis of Spirocyclic Bis-C,C-glycosides. Mechanistic Models in Explanation of Rearrangement Stereoselectivity and the Bifurcation of Reaction Pathways. J. Org. Chem. 1997, 62,1713-1722. 

In a reapplication of the cyanohydrin synthesis to L-rhamnose, the crystalline T-deoxy-L-jfZj/cero-L-gfalacto-heptose was further characterized as the pentaacetates and methyl glycosides. The heptoses derived from D-galactose and n-mannose have been prepared by the nitromethane synthesis, and this can be the method of choice for sugars which are not preferred epimers in cyanohydrin synthesis. 

Synthesis from o-galactose Methyl a-D-galactopyranoside (5) has been converted to 1-deoxygalactonojirimycin (4) (Scheme 2). Thus, methyl 2,3,4-tri-O-benzyl-... 

In the second synthesis of phytosphingosine, outlined in Scheme 3, Gigg s group13 made possible the preparation of 1,3,4-tri-O-benzyl-L-galactitol 23 from D-galactose in good yield. They proved 23 to be an efficient starting material. 

---