A NOVEL SYNTHESIS OF THE 1β-METHYLCARBAPENEM KEY INTERMEDIATE EMPLOYING THE -CYCLOADDITION REACTION OF CHLOROSULFONYL ISOCYANATE WITH A 4H-1,3-DIOXIN DERIVATIVE

Article abstract of DOI:10.1016/S0040-4039(01)93817-1

A highly stereoselective synthetic route to the title compound was explored by featuring the <2+2>-cycloaddition reaction of chlorosulfonyl isocyanate with the 4H-1,3-dioxin derivative readily obtainable from methyl (R)-3-hydroxybutyrate, the Baeyer-Villinger reaction resulting in novel cleavage of the acetal moiety, and the Reformatsky reaction with sterically crowded 3-(2-bromopropionyl)-2-oxazolidone derivatives.