Syntheses of Carbocyclic Analogues of α-<scp>d</scp>-Glucosamine, α-<scp>d</scp>-Mannose, α-<scp>d</scp>-Mannuronic Acid, β-<scp>l</scp>-Idosamine, and β-<scp>l</scp>-Gulose

Abstract

A versatile synthesis of orthogonally protected derivatives of carba-α-D-glucosamine, carba-α-D-mannose, carba-α-D-mannuronic acid, carba-β-L-idosamine, and carba-β-L-gulose from methyl α-D-mannoside is described. Our synthetic strategy utilizes the palladium-promoted Ferrier carbocyclization and persistent butane-2,3-diacetal protection to produce a key chiral cyclohexanone intermediate, from which all five carbasugar derivatives can readily be obtained.