Nucleophilic additions to cyclic nitrones en route to iminocyclitols - Total syntheses of DMDP, 6-deoxy-DMDP, DAB-1, CYB-3, nectrisine, and radicamine B

Highly diastereoselective nucleophilic additions to cyclic nitrones derived from L-malic acid and D-arabinose have been used for the construction of enantiomerically pure poly-hydroxylated pyrrolidines. The synthetic Strategy adopted was based on an oxidation/reduction protocol involving hydroxyldmine/nitrone pairs and demonstrates the use of reagent- and substrate-derived stereocontrol. In most cases reactions took place with total diastereoselectivity and in quantitative yield, with no purification being necessary. By this strategy, 2-(hydroxymethyl)-, 2-(aminomethyl)-, and 2-aryl-polyhydroxylated pyrrolidines have been prepared with abundant configurational diversity. The use of appropriate substrates and reagents allowed for approaches to DMDP, 6-deoxy-DMDP, DAB-1, CYB-3, nectrisine and radicamine B. Several analogues of these compounds with inverted configuration at one or more stereocenters were also prepared. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).