INSIGHT INTO THE UNUSUAL REACTIONS OF STABILIZED PHOSPHORUS YLIDES WITH LACTOLS. A SPECIFIC INTRAMOLECULAR HYDROXYL GROUP EFFECT LEADS TO HIGH Z-SELECTIVITY.

Article abstract of DOI:10.1016/S0040-4039(00)88450-6

In reactions with stabilized ylides, γ-lactols of ribo configuration afford 90percent Z-olefins.Lactols of arabino configuration give intermediate results.The unusual results in the ribo series completely disappear on protection of the γ-hydroxyl group.