2,7-Anhydro sugar analogue

Conformationally defined bicyclic acetal template and readily differentiated hydroxyl in the 2,7-anhydro sugar analogue 241 makes this synthesis flexible enough for preparation various KDN derivatives. 

Regioselectivity is lost with flexible anhydro sugar analogues. 

Reaction of 1,6-anhydro-il, 6 - -benzylidene-3-maltose with 1,3-dlchloro-l,l,3,3-tetraisopropyldislloxane (1.e. TIPS-CI2) in pyridine yielded the 2, 3 -0 -TIPS ether, while the cellobiose analogue yielded the 2,3-0 -TIPS ether (1.e. substituted on the anhydro-sugar moiety). Discrimination between the 2,3- and 2, 3 -hydroxy groups of maltose and cellobiose can be effected in this... 

Reductive cleavage (triethylsilane-trimethylsilyl triilate) of the isopropylidene derivatives 17 gives anhydro-sugars 18. The OH-2 groups in 18 have been further converted to mediates and displaced with purine bases or azide (further converted into a pyrimidine ring) to lead to nucleoside analogues. ... 

Inorganic Derivatives.- 1,6-Anhydro 2-chloro-2,4-dideoxy-4-(diphenylphosphoryl)-P-D-glucopyranose, the P-in-the-ring sugar analogues (27) and (28)," the natural arsenic-containing riboside (29), methyl 4,6-0-benzylidene-3-deoxy-3-C-triphenylstannyl-a-D-altropyranoside, two isomeric chromium(III) complexes with 1,3,5-triamino-1,3,5-trideoxy-cw-inositol in the one structure, the vanadium(in) complex (30),and the platinum(Il)-dithiocarbamate complex (31). ... 

Paulsen s group has reported the synthesis of derivatives (256) and (257) of the hydroxyethyl-branched octose that is found as a component of the quinocycline complexes isolated from Streptomyces aureofaciens. The route from the epoxyketone (255) is outlined in Scheme 59. An identical route was used to prepare branched-chain analogues in the o-series, in which it was shown that acid-catalysed methanolysis of the hydroxyethyl-branched derivative (258) yielded the more stable isomer (259) via the anhydro-sugar d-(257). Paulsen s group has also described a synthesis of a derivative (260) of pillarose (see Vol. 9, p. 99), a component of the antibiotic pillaromycin, using the dianion (261) prepared from 2-hydroxymethyl-l,3-dithiane to introduce the branch at C-4 (Scheme 60). A similar approach, using the anion derived from 2-methyl-l,3-dithiane, and subsequent desulphurization and reduction, etc., was adopted in a synthesis of a derivative (262) of aldgarose (4,6-dideoxy-3-C-[(i )-l-hydroxyethyl]-D-W6o-hexopyranose 3,3 -cyclic carbonate) (cf. Vol. 8, p. 100). 

S. Ogawa and D. Aso, Chemical modification of the sugar moiety of methyl acarviosin synthesis and inhibitory activity of eight analogues containing a 1,6-anhydro bridge,... 

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