Synthetic Studies on Sorigenins. I. Syntheses of γ-Lactones of 1-Methoxy-3-hydroxymethyl-2-naphthoic Acid and 3-Hydroxymethyl-4-methoxy-2-naphthoic Acid
Facile generation and trapping of α-oxo-o-quinodimethane; a synthesis of 3-aryl-3,4-dihydroisocoumarins
作者:Satinder V. Kessar、Paramjit Singh、D. Venugopal
DOI:10.1039/c39850001258
日期:——
Treatment of o-(trimethylsilylmethyl)benzoyl chloride (1) with fluoride ions in the presence of aromatic aldehydes and alkyl fumarates gives 3-aryl-3,4-dihydroisocoumarins (3) and substituted α-tetralones (4), respectively.
Facile generation and trapping of .alpha.-oxo-o-quinodimethanes: synthesis of 3-aryl-3,4-dihydroisocoumarins and protoberberines
作者:Satinder V. Kessar、Paramjit Singh、Rahul Vohra、Nachhattar Pal Kaur、D. Venugopal
DOI:10.1021/jo00051a009
日期:1992.12
Fluorodesilylation of o-((trimethylsilyl)methyl)benzoyl derivatives 5 in the presence of aromatic aldehydes and alkyl fumarates gives 3-aryl-3,4-dihydroisocoumarins 6 and alpha-tetralones 10, respectively. Reaction of 5 with 3,4-dihydroisoquinolinium salts 19 leads to 8-oxoberbines 21. Using this procedure, racemic hydrangenol, phyllodulcin, tetrahydropalmatine (22a), and canadine (22b) have been synthesized.
KESSAR, S. V.;SINGH, PARAMJIT;VENUGOPAL, D., J. CHEM. SOC. CHEM. COMMUN., 1985, N 18, 1258-1259
Synthetic Studies on Sorigenins. I. Syntheses of γ-Lactones of 1-Methoxy-3-hydroxymethyl-2-naphthoic Acid and 3-Hydroxymethyl-4-methoxy-2-naphthoic Acid
As an exploratory experiment on syntheses of sorigenins (I), 1-methoxy-3-hydroxymethyl-2-naphthoic acid γ-lactone (VIII) and 3-hydroxymethyl-4-methoxy-2-naphthoic acid γ-lactone (XV) were synthesized. Compound (VIII) was prepared from 3-hydroxymethyl-3, 4-dihydro-1 (2H)-naphthalenone (IV) as shown in Chart 1. Compound (XV) was prepared through reduction of 3-ethoxycarbonyl-4-hydroxy-2-naphthoic acid (XVIII) and its methyl ether (XX) with lithium aluminium hydride. Reductions of 1-methoxy-2, 3-naphthalenedicarboxylic anhydride (XIV) and of the halfester prepared by alcoholysis of (XIV) with lithium aluminium hydride were found to give a mixture of (VIII) and (XV).