3-halo-6-hydroxy-2H-pyran-3 (6H) -one sommellemprodukter compounds for use in the preparation of gamma-pyrones and method of preparation of the intermediate compounds

摘要

1. 4-halogen-6-hydroxy-2H-pyran-3(6H)-one compounds for use as intermediates in preparation of gamma-pyrones of formula: IMAGE, I where R means hydrogen, alkyl with 1-4 carbon atoms, phenyl or benzyl, and R''' means hydrogen or alkyl with 1- 4 carbon atoms, characterized in that they have the general formula: IMAGE, II' where R and R''' have the above meaning, and X means chlorine or bromine.