Regio- and stereoselective Ferrier reaction of O-1,3-dienyl acetals promoted by organoaluminum complexes

The Ferrier reaction of O-1,3-dienyl acetals promoted by organoaluminum complexes such as methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide) (MAD) is shown to proceed with a high degree of regio- and stereoselectivity to afford the corresponding alpha-alkenyl-substituted beta-alkoxy aldehydes in good yields. The mechanistic origin of the high regiocontrolling ability of MAD is elucidated. This method, coupled with the easy availability of the requisite substrates, expands the synthetic scope of the Ferrier reaction. [reaction: see text].