Z-Selective intramolecular Horner-Wadsworth-Emmons reaction for the synthesis of macrocyclic alkenes

The Z-selective intramolecular Horner-Wadsworth-Emmons reaction of the substrates (Ar = Ph or o-tBuC6H4) gives the 13-18-membered cyclic alkenes selectively (up to Z:E = 97:3) in good yields using NaH in THF under high dilution conditions.