The total synthesis of 8-epi, 8,9-epi, and 9-epi-(−)-cephalimysin A is described. Our catalytic enantioselective synthesis takes advantage of a novel tandem photoisomerization/Stetter reaction. The approach provides rapid access to the desired spirofuranone lactam core in good yield and excellent enantioselectivity. A late stage oxidation strategy allows for flexible access to three of the four diastereomers of cephalimysin A. Access to the epimers provides further support for the correction of the initially proposed relative stereochemistry of cephalimysin A.

A photoisomerization-coupled asymmetric Stetter reaction: application to the total synthesis of three diastereomers of (−)-cephalimysin A

Synthesis of spiroacetal enol ethers by oxidative activation of furan derivatives.

Protecting group and solvent control of stereo- and chemoselectivity in glucal 3-carbamate amidoglycosylation.

A highly stereoselective BF3·OEt2-promoted tandem hydroamination–glycosylation on a glycal scaffold has been developed to form 3-amino-2,3-dideoxysugars in a one-pot procedure. This efficient multicomponent reaction protocol offers simplicity and general applicability to a broad range of variations on each component.

Ready access to 3-amino-2,3-dideoxysugars via regio- and stereo-selective tandem hydroamination–glycosylation of glycals

Total syntheses of spirocyclic PKS-NRPS-based fungal metabolites.

Synthesis of α‐2‐Deoxyglycosides by Acid‐Mediated Conjugate Addition

Synthetic studies of spiroketal enol ethers: an unexpected oxidation by Martin’s sulfurane

A new method for the synthesis of α‐2‐deoxyglycosides from hex‐1‐en‐3‐uloses is reported. Several acids were surveyed for their ability to mediate the conjugate addition of cyclohexanol to a glucal derived α,β‐unsaturated ketone. Although several acids successfully afforded the α‐2‐deoxy‐3‐uloside as a single anomer, Ph3P  · HBr in benzene afforded the highest yield of product. These conditions were then applied to other alcohol nucleophiles, and it was found that nonsterically hindered alcohols readily undergo conjugate addition. Finally, the stereoselectivity of reduction of the resulting α‐2‐deoxy‐3‐uloside was determined for several hydride‐reducing agents.

Jennifer Koviach

Papers

Synthesis of α‐2‐Deoxyglycosides by Acid‐Mediated Conjugate Addition

Synthetic studies of spiroketal enol ethers: an unexpected oxidation by Martin’s sulfurane

Synthesis of α-2-Deoxyglycosides by Acid-Mediated Conjugate Addition.