A convenient approach to the construction of dihydroxylated unsaturated azepanes featuring a functional group (ethoxycarbonyl) methyl or (cyano) methyl at C-2 was achieved from a pent-4-enal synthon obtained in four steps from d-xylose. The key step of the sequence relied on the conjugate addition of allylamine to α, β-unsaturated ester or nitrile, prepared by Wadsworth–Emmons olefination. Subsequent RCM afforded the target unsaturated ...
