Short Syntheses of Gabosine I and Gabosine G from δ-d-Gluconolactone

A short synthesis of gabosine I (1) from δ-d-gluconolactone (3) in four steps, involving a one-pot TPAP oxidation−K₂CO₃-mediated intramolecular Horner−Wadsworth−Emmons (HWE) olefination as the key step, is described. Regioselective acetylation of the primary alcohol in gabosine I (1) then furnished gabosine G (2).