| ection I. The new disaccharide, crystalline (6-deoxy-;Section II. Approaches to chain extension at the C-6 positions in cyclomaltoheptaose (2) were examined with the aim of producing novel beta-cyclodextrin analogs composed of heptose or hepturonic acid units. Ironcarbonyl-mediated methoxycarbonylation, and nucleophilic displacement by cyanide, in the fully acetylated heptakis(6-deoxy-6-iodo) and heptakis(6-O-mesyl) derivatives of 2 respectively were unsuccessful, as were similar reactions attempted with the newly synthesized, analogous allyl-protected derivatives of 2. However, reaction of unprotected heptakis(6-deoxy-6-iodo)cyclomaltoheptaose with lithium cyanide in N,N-dimethylformamide afforded a high yield of the corresponding heptakis(6-cyano-6-deoxy) compound, i.e., cyclohepta-(;Section III. An approach to the synthesis of 3-deoxy-D-manno-2-octulosonic acid (KDO) 1 by the ironcarbonyl method of chain-elongation starting from methyl... |
