The addition of (i-PrO)(3)TiCH3 to gamma-hydroxybutenolides having a chiral center with an alkoxy group adjacent to the ketone functionality (of the open chain form) gave gamma-lactones in good yields and high diastereoselectivity.
Title
Diastereoselective addition of organotitanium reagents to chiral gamma-hydroxybutenolides
Miles, W. H., et al. (2007) "Diastereoselective addition of organotitanium reagents to chiral gamma-hydroxybutenolides." Heterocyclic Communications 13 (4): 195-198.