Conjugate addition Ramberg-Backlund reaction

Evans, P., Taylor, R. J. The epoxy-Ramberg-Backlund reaction a new route to allylic alcohols. Tetrahedron Lett. 1997, 38, 3055-3058. Evans, P., Taylor, R. J. K. Novel tandem conjugate addition/Ramberg-Backlund rearrangements. Syniett 1997,1043-1044. 

A novel tandem process has been reported " for the preparation of allylic amines, ethers, and sulfides from a-bromo-a, jS-unsaturated sulfones. The process is believed to proceed via an initial conjugate addition followed by proton exchange and Ramberg-Backlund rearrangement (see Scheme 75). A new variant of the Ramberg-Backlund reaction has been described in which a, /f-epoxy sulfones (319), on treatment with base, are converted into a range of mono-, di-, and tri-substituted allylic alcohols (320). 

The overall process involving addition of a-bromomethanesulfonyl bromide to olefins and subsequent dehydrobromination followed by base-promoted viny-logous Ramberg-Backlund reaction constitutes a three-step transformation of olefins into 1,3-dienes (Scheme 14) [107]. Conjugated dienes are also available from the Ru(II)-catalyzed reaction of alkenesulfonyl chlorides with olefins [108],... 

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