First Friedel−Crafts Diacylation of a Phenanthrene as the Basis for an Efficient Synthesis of Nonracemic [7]Helicenes
作者:Kamil Paruch、Thomas J. Katz、Christopher Incarvito、Kin-Chung Lam、Brian Rhatigan、Arnold L. Rheingold
DOI:10.1021/jo001055m
日期:2000.11.1
first examples of Friedel-Crafts reactions used to prepare 3,6-diacylphenanthrenes. 9,10-Dimethoxyphenanthrene gives its 3,6-diacetyl derivative in good yield and in large amounts. The ketone's triisopropylsilyl enol ether when combined with 1, 4-benzoquinone forms a [7]helicenebisquinone. This bisquinone's reduction product, a bishydroquinone, when combined with methanolic HCl gives the [7]helicene