Coupling of Acetylene and Aldehydes Applied to l-Hexoses Synthesis

Significance

A ligand-controlled stereoselective formal butadiene addition to α-branched aldehydes is reported. By simply using enantiomeric MeO-BIPHEPs, diastereomeric allylic alcohols can be obtained with good to high selectivity. The substrate chirality can be overridden by the catalyst even in mismatched cases. The synthetic utility of the method was demonstrated by intercepting four intermediates that have been used in the synthesis of all eight l-monosaccharides by Sasaki and Ermolenko (J. Org. Chem. 2006, 71, 693).