Facile generation and trapping of. alpha.-oxo-o-quinodimethanes: synthesis of 3-aryl-3, 4-dihydroisocoumarins and protoberberines

SV Kessar, P Singh, R Vohra, NP Kaur…

Index: Kessar; Singh; Vohra; Kaur; Venugopal Journal of Organic Chemistry, 1992 , vol. 57, # 25 p. 6716 - 6720

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Citation Number: 28

Abstract

Fluorodesilylation of o-((trimethyleily1) methyl) benzoyl derivatives 5 in the presence of aromatic aldehydes and alkyl fumarates gives 3-aryl-3, 4-dhydro~ oumarina 6 and a- tetralones 10, respectively. Reaction of 5 with 3, 4-dihydroieoquinolinium salts 19 leads to 8- oxoberbines 21. Using this procedure, racemic hydrangenol, phyllodulcin, tetrahydropalmatine (224, and canadine (22b) have been synthesized.