| 摘要 |
The preparation 4-halo-dihydropyran intermediates by reacting (i) a substituted or unsubstituted 2H-pyran-3(6H)-one with at least one equivalent, or (ii) a furfuryl alcohol with at least two equivalents, of a halogen-contain-ing oxidant, selected from chlorine, bromine, bromine chloride, hypochlorous acid, hypobromous acid or a mixture thereof; and novel 4-halo-dihydro-pyran intermediates. |
