145694-71-9Relevant academic research and scientific papers
Cyclisation and subsequent reactions of 2′-hydroxy-6′-methoxychalcone epoxide and related compounds
Adams, Christopher J.,Main, Lyndsay
, p. 4979 - 4990 (1991)
2′-Hydroxy-6′-methoxychalcone epoxide reacts in neutral aqueous acetonitrile solution to give a 6:1 ratio of the α- and β-cyclisation products, erythro-4-methoxyaurone hydrate [erythro-2-(α-hydroxybenzyl)-4-methoxycoumaran-3-one] and trans-3-hydroxy-5-methoxyflavanone: the dominance of α-cyclisation may be associated with a stereoelectronic preference for a conformation favourable for α- but not β-cyclisation when the carbonyl group is forced by the 6′-substituent to lie out-of-plane with the aromatic ring. In more basic solutions, erythro-threo isomerisation of aurone hydrate occurs, and 4-methoxycoumaran-3-one and 4-methoxyaurone are formed. Other 6′-substituted 2′-hydroxychalcone epoxides show a similar strong preference for α- over β-cyclisation.
