From Free-Phenolic Units with a Good 7-Leaving Group

1 From Free-Phenolic Units with a Good 7-Leaving Group 

An alternative method, as long as acetylation is not a concern elsewhere in the molecule, is to produce free-phenolic 7-acetates Pl-Ac (Fig. 12.4a, lower scheme). The quinone methides QM1 or QMl-Ac can then be generated in situ by treatment 

The quinone methide can also be generated in situ, at least in aqueous NaOH, directly from the peracetate, as hydrolysis of the phenolic acetate is faster than the benzylic acetate (see an example in Section 12.5.3). This method was used to demonstrate the addition of anthrahydroquinone (AHQ) and anthranol to (actual polymeric) lignin quinone methides in studies elucidating the anthraquinone (AQ)-catalyzed 8-0-4-aryl ether cleavage mechanisms in alkaline pulping.64-66 

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