Pentodialdose, xylo

In the preparation of polyhydroxylated azepane as potential glycosidase inhibitors, Dha-vale [28] described a short synthetic route utilizing the Henry approach. The nitroaldol reaction of l,2-0-isopropylidene-3-0-benzyl-a-D-xylo-pentodialdose 36 and nitromethane in the presence of triethylamine at room temperature afforded a-D-gluco- and /3-L-ido- nitroal-dose 37, the precursors to (2S, 3R, 4R, 5R) and (2S, 3R, 4R, 55) tetrahydroxyazepanes 38 and 39, in a 88 12 ratio in 95% yield (O Scheme 13). 

Some other derivatives of xylo-pentodialdose (8) have been obtained by... 

Mester and M6czdr prepared the formazan of 1,2-0-isopropylidene-a-D-a 2/Zo-pentodialdo-l, 4-furanose and the bis(formazan) of the free xylo-pentodialdose (see Hester s review ). 

The reaction sequence of Grosheintz and Fischer,98,102 namely, 87 — 88 + 89 — 90 + 91 — 100 + 101 +102, constitutes a stepwise, nitromethane cyclization of xylo-trihydroxyglutaric dialdehyde (99) (xy(o-pentodialdose), a partially protected derivative of which is 87. 

The B-carboline derivative 85 was isolated as a natural product from a hybrid plant cell culture. It was synthesized from tryptamine and (E)-4,5,6-tri-0-acetyl-2,3-dideoxy-D-erythro-hex-2-enose. Condensation of tryptamine with 1,2-0-cyclohexyMene o-xylo-pentodialdose gave tetra-hydro analogue 85a [143-145]. 

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