In this paper we describe the unprecedented reaction between alpha-diazo esters 1 and iodine. The reaction, carried out in the presence of aqueous NaHCO3, afforded the Z-isomer of the corresponding unsaturated-2-iodo ester 8. The configuration of compounds 8 was determined using the 3J(C-H) coupling between carbonyl carbon atom and alkene proton. Mechanistic considerations accounting for the observed phenomena and including quantum chemical calculations are proposed.
