De Novo Synthesis of Furanose Sugars: Catalytic Asymmetric Synthesis of Apiose and Apiose‐Containing Oligosaccharides

A de novo synthetic method towards apiose, a structurally unusual furanose, is reported. The key feature is sequential metal catalysis consisting of the palladium‐catalyzed asymmetric intermolecular hydroalkoxylation of an alkoxyallene and subsequent ring‐closing metathesis (RCM). This strategy enabled the efficient synthesis of various apiose‐containing disaccharides and a unique convergent synthesis of trisaccharides.