Synthesis of 1,2-Difunctionalized 1,3-Butadienes through a Sequence of Sigmatropic Rearrangements

Just by the introduction of isomerizable groups and successive [3,3] or [2,3] rearrangements, the diols 1 can be transformed into the new synthetic building blocks 2. The conversion often proceeds with high stereoselectivity or even stereospecificity, and in some cases in a one-pot reaction. X, Y=NHCOCCl3, N3, P(O)Ph2, 4-SO2C6H4Me, S(O)Ar, SCOR.