E. Piers et al., A CONVENIENT PROCEDURE FOR THE EFFICIENT PREPARATION OF ALKYL (Z)-3-IODO-2-ALKENOATES, Canadian journal of chemistry, 72(8), 1994, pp. 1816-1819
Reaction of alkyl 2-alkynoates with sodium iodide (1.6-5.5 equiv.) in
acetic acid (6.2-13 equiv.) at 115 degrees C provides good to excellen
t yields of the corresponding alkyl (Z)-3-iodo-2-alkenoates.