Oxygenated phenanthrenes via quinol ketals: Cyclization vs. migration
2-methoxyphenanthrenes were prepared by reaction of lithiated 2-bromostyrenes with quinone monoketals followed by acid-mediated cyclization of the resulting p-arylquinol ketals. Substitution at the bromostyrene side-chain or the quinone monoketal ring had only a modest effect on yields, but oxygen substitution on the bromostyrene aromatic nucleus resulted in a competing 1,2-aryl migration arising during the quinol ketal cyclization step. The extent of this rearrangement was found to be a function of the Lewis acid/solvent system employed.
Morrow, Gary W.,Marks, Tina M.,Sear, Debra L.
p. 10115 - 10124
(2007/10/02)
A CONVERGENT APPROACH TO SUBSTITUTED PHENANTHRENES VIA QUINOL KETALS
Reaction of 2'-lithiostyrenes with p-benzoquinone monoketals gives p-quinol ketals which undergo Lewis acid-catalyzed cyclization and aromatization, affording 2-methoxyphenanthrenes.
Marks, Tina M.,Morrow, Gary W.
p. 2269 - 2270
(2007/10/02)
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