Formal Synthesis\nof Amipurimycin and 4′-Deoxymiharamycin\nB by Way of Sequential Asymmetric Metal Catalysis

Herein, we describe a highly efficient\nformal synthesis of nucleoside\nantibiotics amipurimycin and 4′-deoxymiharamycin B. A signature\nevent is highlighted by the sequential metal catalysis combining (i)\nPd-catalyzed asymmetric hydroalkoxylation of an alkoxyallene; (ii)\nRu-catalyzed enyne-methathesis, and (iii) Os-catalyzed dihydroxylation.\nRemarkably, this atom-efficient sequence allows for the construction\nof a 3′-branched pyranose core structure in only four steps\nfrom readily available Garner’s aldehyde.