HAUSER-KRAUS Annulation

A Hauser-Kraus annulation of the ortho-acetyl cinnamate 792 with phthalides affords naphtho[c]-isocoumarins in high yield (Scheme 218) <2004TL7895>. 

HAUSER-KRAUS Annulation Regioselective annulation of phthalides to naphthalene hydroquinone. 

The benzonaphthopyranone system 47, the basic structure of the gilvocarcins, has been assembled in one step using a Hauser-Kraus annulation. The key feature is the incorporation of a suitably placed ester function in the Michael acceptor which generates the lactone ring. Thus, isobenzofuranones and esters of ethyl citmamate form the tetracycle directly in high yields. Methyl 6-methylcoumarin-5-carboxylate behaves in an identical manner providing a total synthesis of the pentacycle chartarin <04TL7895>. 

The regioselective synthesis of complex aromatic compounds has been an important and active research area for chemists over decades. Various strategies and documented synthetic methods have found favor for the synthesis of aromatic compounds. These would include the use of Diels-Alder reactions, Friedel-Crafts methodology, and a range of annulation methods such as those developed by Hauser, Kraus, Staunton, and Weinreb, as well as a range of transition... 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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