Intramolecular Diels–Alder reaction of α-fluoroacrylate derivatives promoted by novel bidentate aluminum Lewis acid

Intramolecular Diels–Alder (IMDA) reaction of α-fluoroacrylate derivatives 1a–e having 1,7,9-decatrienoate system is efficiently promoted by the novel bidentate Lewis acid A generated in situ by mixing 3,3′,5,5′-tetrabromo-1,1′-biphenyl-2,2′-diol (Br4BIPOL, 1 mol) and trimethylaluminum (2 mol). The IMDA reaction of α-fluoroacrylates proceeds via endo-boat transition state as in the case of the corresponding non-fluorinated acrylate.