Fully synthetic stereoselective routes to the differentially protected subunits of the tunicamycins

Article abstract of DOI:10.1021/ja00197a047

Total synthesis of the two subunits corresponding to tunicamycins have been achieved. One of the key steps involves a cyclocondensation reaction of 7-carbon aldehydo nucleoside with activated diene 8 under catalysis with stannic chloride (see 7 + 8→9a,b). Stereospecific Fitzsimmons cycloadditions of dibenzyl azodicarboxylate to galactal 12 and glucal 22 simplified construction of the amino pyranose systems.