The chlorination of dihydroconiferyl alcohol

Abstract

Aqueous chlorination of dihydroconiferyl alcohol, a phenol present in pulping liquors, gave a mixture of three products. The two major products, which formed an inseparable mixture, yielded the crystalline epoxides 1 and 8 when reacted with diazomethane. The epoxide 1 had previously been obtained by reacting one of the components isolated from mutagenic fractions of chlorination-stage effluent from a bleached kraft pulp mill with diazomethane. The results indicate dihydroconiferyl alcohol retained with pulp is chlorinated in the bleach plant to give a mixture of the spirocyclohexenediones 5 and 6. Crystals of 8 are orthorhombic, a = 24.3048(15), b = 12.5403(9), c = 7.8653(6) Å, Z = 8, space group Pbca. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.029 and Rw = 0.035 for 1308 reflections with I ≥ 3σ(I). The structure analysis shows that 8 has the same relative stereochemistry as that reported earlier for 1, but exists as a different conformer in the solid state.