Analysis of the pH-rate profile for the cyclisation of the monoanion of 2′-hydroxychalcone epoxide which gives 3-hydroxyflavanone and of some 6′-alkoxy-substituted analogues which give mostly hydrate, gives rate coefficients which quantify the preference for α over β cyclisation when 6′-substituents are present. These are considered in terms of stereoelectronic factors which may be responsible for the preference. Also reported are ...
