Ortho Ester Claisen Rearrangements of Three 3-C-(Hydroxymethyl)methylene Derivatives of Hexofuranose: Stereoselective Introduction of a Quaternary Center on C-3 of D-ribo-, L-lyxo-, and D-arabino-Hexofuranoses

Article abstract of DOI:10.1021/jo00383a005

Ortho ester Claisen rearrangements of (E)-3-deoxy-3-C-<(hydroxymethyl)methylene>-1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranose (3-E), -β-L-lyxo-hexafuranose (12-E), and -β-D-arabino-hexofuranose (33-E) proceeded with high stereoselectivity to provide the rearranged products 13, 15, and 34, respectively, in acceptable yields.The rearrangements of the corresponding Z isomers 3-Z, 12-Z, and 33-Z were also investigated.The stereochemistries of the newly introduced quaternary center on C-3 of compounds 13, 15, and 34 were established unambiguouosly by chemical modifications of each rearranged product.