A Family of Routes to Substituted Phenols, Including Meta-Substituted Phenols

A new family of routes
to substituted phenols has been developed.
2-Bromo-3-methoxycyclohex-2-en-1-ones are readily deprotonated at
C-6, and the resulting anions react smoothly with a variety of electrophiles;
treatment with DBU in PhMe at room temperature then results in efficient
aromatization to benzene derivatives of a regiochemically defined
substitution pattern. This sequence affords phenolic azides (ArN3), sulfides (ArSR, ArSAr′), selenides (ArSePh), alcohols
[ArCH­(OH)­R], amino derivatives [ArCH­(NHSO2Ar′)­R),
and 1,2-benzenediols. A complementary set of substitution patterns
is obtained by DIBAL-H reduction or reaction with a Grignard reagent
before aromatization; the latter process gives compounds in which
the newly introduced substituent is meta to the phenolic hydroxyl.