Heptitol derivatives

This sequence involves a Henry reaction of 41 with nitromethane followed by a dehydration of the resulting acyclic D-heptitol derivative 42 and a Michael intramolecular addition of the resulting nitroolefin 43. 

Alcohol 470 was also converted to 3-deoxy-D-araZ m6>-heptulosonic acid [213b] and to enantio pure 2-deoxyhexoses [213c]. Cycloheptatrienone (tropone) has been converted into heptitol derivatives via the optical resolution of the (tropone)Fe(CO)3 complex [213d]. 

It is interesting that iron carbonyl can be used as a protecting group for dienes. Iron diene complex 491, for example, reacted with 492 in a Mukaiyama aldol reaction (sec. 9.4,C), giving an 81% yield of 493 and 494 in an 84 16 ratio.32 in a synthesis of heptitol derivatives,322 Pearson protected tropone as the iron tricarbonyl derivative (495), and prepared 496 using a multistep sequence before deprotecting the diene to give 497. 

From Chiral Non-carbohydrates - A section on amino-sugars has been included in a review of the synthesis of monosaccharides from non-carbohydrate sources. L-Ristosamine 42 was synthesized by addition of the Cs-synthon 40 (which contains a masked aldehyde function that can be readily demasked by mild acid hydrolysis) to the L-lactaldehyde derivative 41 (Scheme 11). The TBSOP adduct 43 (Vol.27, p.ll4), derived from 2,3-< -isopropylidene-D-glycer-aldehyde, has been converted into 3-amino-3-deoxy-D-altrose 46 by a route involving cis-hydroxylation of its unsaturated lactam moiety and periodate cleavage between C-6 and C-7 of the derived heptitol derivative 45 as key steps (Scheme 12). 3-Amino-3-deoxy-L-allose was obtained by converting 43 to its C-3... 

A number of 1-deoxy-l-nitro-hexitol and -heptitol derivatives... 

In 1987 2,6-dideoxy-2,6-imino-D-g(ycero-L-gM/o-heptitol (14), a chain-extended derivative of 1-deoxynojirimycin, was synthesized as a potential glucosidase inhibitor [50] and soon thereafter extracted from the leaves of the Panamesian plant Omphalea diandra L [51]. Coined a-homonojirimycin by the discoverers, this novel type of inhibitor exhibited pronounced activity against gluco-... 

Certain synthetic heptitols that could not be separated by paper chromatography or by electrophoresis have been separated as their O-trimethylsilyl derivatives.404 The procedure of reductive, alkaline hydrolysis, much used in glycopeptide research, yields alditols that have been estimated as their trimethylsilyl ethers,59,405 and D-glucitol in mammalian nerve has similarly been determined.406... 

D-g/ycero-D-gM/o-heptitol afforded the xylodialdose derivative 173 by oxidation with sodium metaperiodate.378... 

Condensation of 2,3-O-isopropylidene-D-glyceraldehyde-A -benzylimine 211 with 2-(tri-methylsilyloxy)furan in the presence of a Lewis acid generates a mixture of butenolides 212 that is converted into D-nZ 6>-A, A -diprotected derivative 213 in 68% yield (Scheme 13.67) [119]. Dihydroxylation of 213, followed by diol protection and lactone reduction, furnishes the 5-amino-5-deoxyheptose derivative 214. Hydrogenolysis in MeOH generates 215 and its deprotection furnishes enantiomerically pure l,5-dideoxy-l,5-imino-D-g/yc r6>-D-a//6>-heptitol 216 [120]. 

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