We have begun a new programme to investigate, in-depth, the effect of stereocentres outside the six-membered pericyclic array upon the stereochemical outcome of Claisen rearrangements. 3 The Belluš–Claisen rearrangement 4,5 was selected as the basis of the new study. 6 In this version of the transformation, the highly reactive electrophile dichloroketene is intercepted by an allylic ether , thioether or tertiary amine , and the resulting zwitterionic ...
