Monomeric Cyclic Imino-alditols

For convenience, the syntheses of cyclic imino-alditols are now categorized broadly according to whether they stem from carbohydrate or non-carbohydrate sources. Compounds derived from carbohydrate sources are further categorized according to their method of synthesis. 

D-Arabinose has been used as starting material for an eight step preparation of l,4-dideoxy-l,4-imino-L-xylitol. Ring closure was effected by a double displacement of the mesylate groups in the intermediate 2,3,5-tri-0-benzyl-l,4-di-0-methanesulfonyl-D-arabinitol with benzylamine.  

Ga/acfo-isofagomine analogue 32, a modest inhibitor of p-galactosidase, was also synthesized from D-arabinose in 12 steps via chain extension at C-2 and 

Reagents i, NH2NH2, Br2 dioxane ii, aq. KOH then cone. HCI Hi, AC2O, cat. HCIO4 iv, LiAIH  

A rapid route to N-substituted trihydroxypiperidines (l,5-dideoxy-l,5-imino-pentitols) by nucleophilic opening of bis-epoxides derived from d- and L-ara-binitol, D-xylitol and related compounds has been reported. The 3-0-benzyl-Zn s-epoxides, generated by tosylation of the primary hydroxyl groups followed by treatment with sodium hydride and benzyl bromide, were treated with primary amines to yield piperidine/pyrrolidine mixtures, whose composition was found to be dependent on the nature of the alditol precursor, the amine and the reaction 

---