Sugar synthesis hydrazones

Dimethyl-l,3-dioxan-5-one SAMP/RAMP hydra-zones j were used as dihydroxyacetonephosphate equivalents in the synthesis of C2 symmetric ketones (eq 5), aza sugars with novel substitution patterns, or C5 to C9 deoxy sugars. SAMP hydrazones of 2-oxo esters represent novel phosphoenolpyruvate (PEP) equivalents. a,a-Disubstituted spiroacetals are accessible via the alkylation of ketone SAMP/RAMP hydrazones. ... 

Acenaphtheno[l,2-e][l,2,4]triazolo[4,3-h][l,2,4]triazine 747 was prepared (79AP147) by cyclizing 3-hydrazinoacenaphtheno[l,2-e][l,2,4]tria-zine 746 with formic acid. Reaction of 746 with sugars gave the hydrazones, which cyclized with iron(III) chloride to give 748 (93BCJ00). Similarly, the acetaldehyde derivative of 746 was cyclized to 748. The structure of 748 (R = Me) rather than 747 (R = Me) was deduced by unequivocal synthesis of the latter by condensation of acenaphthenequinone with 3,4-diamino[l,2,4]triazole (Scheme 155). 

Enders, D, Jegelka, U, l,3-Dioxan-5-one as C3-building block for the diastereo- and enantioselective synthesis of C5- to Cg-deoxy sugars using the SAMP-/RAMP-hydrazone method. Tetrahedron Lett., 34, 2453-2456, 1993. 

Iii this chapter on the hydrazine derivatives of sugars and related compounds, an attempt has been made to offer more than a review of what has already been achieved by focusing on reactions that have not yet been tried on carbohydrate substrates (examples of these are given in Sections III.3 and IV.4). In summary, a serious effort has been made to point to novel approaches for the synthesis of, and new applications for, the reactions of saccharide hydrazones and their carbocyclic analogs. 

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