作者:S. A. Chesnokov
DOI:10.1023/a:1023931428206
日期:——
Photoreduction of o-benzoquinones in the presence of p-bromo-N,N-dimethylaniline under irradiation (lambda > 500 nm) affords the corresponding pyrocatechols and hydroxyphenyl ethers. The latter are unstable and, in turn, decompose in the dark reaction to pyrocatechols. The ratio between pyrocatechol and hydroxyphenyl ether formed upon the photoreaction is determined by the structure of o-quinone, namely, the presence and bulk of substituents in positions 3 and 6 of the ring. The yield of pyrocatechol is maximal (60-65%) if the substituents are the same (H and H, Bu-t and Bu-t) or insignificantly differ (Pr-i and Bu-t), regardless of its bulk.