Synthesis of monoprotected 2-alkylidene-1,3-propanediols by an unusual SN2′ Mitsunobu reaction

A simple and efficient route to monoprotected E- and Z-2-alkylidene-1,3-propanediols was developed. The key step involves an unusual regio- and stereoselective SN2′ Mitsunobu reaction of substituted 3-hydroxy-2-methylenealkenoate.