The rhodium catalyzed three-component reaction of diazoacetates, titanium(IV) alkoxides and aldehydes

The rhodium(II)-catalyzed three-component reaction of diazoacetates, titanium alkoxides and aldehydes is shown to give (alpha)-alkoxyl-(beta)-hydroxyl acid derivatives; the novel C–C bond formation reaction is proposed to occur through oxonium ylides derived from diazo compounds and titanium alkoxides, and followed by intermolecular trapping by aldehydes.