I Idose

Problem 25.22 What aldopentose would giv e a mixture of i.-gulose and i-idose on Kiliani-l isdier... 

M. L. Wolfrom and S. Hanessian, Reaction of free carbonyl sugar derivatives with organo-metallics reagents. II 6-Deoxy-i.-idose and a branched-chain sugar, J. Org. Chem. 27 2107 (1962). 

Penta-O-benzoyl-a-D-idopyranose, 1-9 l,2,3,4,5-Penta-0-benzyl-i>-idose, 1-9... 

Wolfrom, M L, Hanessian, S, The reaction of free carbonyl sugar derivatives with organometalUc reagents. I. 6-Deoxy-L-idose and derivatives, J. Org. Chem., 27, 1800-1804, 1962. 

More broadly speaking, we can anticipate the following four orientations around the cyclic oxygen of a D-pyranose I and III for trans derivatives, and II and IV for cis (Fig. 2.9). With the exception of idose (and perhaps altrose), all of the trans derivatives, in this case the monocyclic a-D-hexopyranoses and their derivatives, exist under the only observable conformation, d- Ci, which corresponds to the local conformation I, doubly stabilized by the anomeric and coplanar effects. 

Grosheintz and Fischer synthesized the 6-deoxy-6-nitro derivatives of D-glucose and L-idose by treating l,2-0-isopropylidene-a-D-a i/lo-pento-dialdo-l,4-furanose with nitromethane, and employed these sugars for cyclization to cyclitol derivatives. These reactions and their importance in cyclitol chemistry have already been reviewed in this Series. - ... 

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