Conformations of allylic fluorides and stereoselectivities of their Diels-Alder cycloadditions

The preparations of new allylic fluorides from the corresponding alcohols a re reported. Conformational analysis is achieved by comparison of experimen tal NMR measurements with theoretical (B3LYP) calculations of relative ener gies of conformers and J(H,H) and J(H,F) coupling constants. The Diels-Alde r reactions of allylic fluorides are investigated experimentally and theore tically. The stereoselectivities of the reactions were determined by NMR an alysis and, in one case, by X-ray crystallography. Theoretical predictions of stereoselectivity based upon transition state modeling provided good agr eement with experiment. Theoretical models for allylic fluorides and transi tion state conformations are reported.