Synthesis of Glycocinnasperimicin D

The first total synthesis of amino sugar antibiotic glycocinnasperimicin D (1) has been achieved by a convergent, three‐component coupling strategy. The key steps involve the Heck–Mizoroki reaction by using the iodophenyl glycoside 50 and acryl amide 32 to furnish the right core structure of 1, and the construction of the urea glycoside employing the reaction of glycosyl isocyanate 8 with amino sugar 9. Glycosyl isocyanate 8 was prepared by the oxidation of isonitrile 10, which displayed excellent reactivity in the coupling event. Synthetic roadblocks, encountered during this synthetic effort, have led to the development of the α‐selective, Lewis acid catalyzed phenyl glycosylation process with 2‐amino‐hexopyranose and a procedure for acetonide deprotection without affecting the silyl ethers. Nitrogen‐rich antibiotic: The synthetic venture of glycocinnasperimicin D, an amino sugar antibiotic decorated with a variety of nitrogen‐containing functional groups, has been completed by a three‐component coupling strategy (see scheme). The convergent tactic is realized by the Heck–Mizoroki reaction and construction of the urea glycoside by the reaction of glycosyl isocyanate with an amino sugar.