1983 Volume 37 Issue 11 Pages 1011-1017
Various oxo-derivatives having different oxidation stages were produced by the treatment of ferruginol with chlorine followed by chlorine dioxide (CD1) and all of them were proved to be directly responsible for difficulties in bleaching UKP from sugi woods (Cryptomeria japonica). The plausible reaction pathways for the products are given in Figure 4.
When the products obtained by the CD1 treatment of ferruginol are again treated with chlorine dioxide (CD1D2), apparent but not much reduction in yields of the coloured oxo-derivatives (4, 8, & 8') and the postulated precursors (7 & 5) for 8 & 8' compared to those of five compounds afforded by CD, can be observed. However, the reaction rate of any stage of chlorination, oxidation, and decomposition is slow enough to leave much amounts of harmful products of different oxidation stage even after the treatment CD1D2. The distinguished stabilities might be primarily attributed to unusually high steric hindrance around the phenolic group in the molecule of ferruginol and its derivatives. This explains the characteristic features of difficulties in bleaching sugi UKP by the method of conventional multi-stage bleaching of CED (or H) ED.
