Synthetic Transformations of Higher Terpenoids. 38. Synthesis of Conjugates Containing β-Carboline and Tricyclic Diterpenoids

• Published in: Chemistry of natural compounds Vol. 55; no. 5; pp. 871 - 877
• Main Authors: Gromova, M. A., Kharitonov, Yu. V., Rybalova, T. V., Shul’ts, E. E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-09-2019; Springer Nature B.V
• Subjects: Aluminum oxide; Chloroform; Medicine; Organic Chemistry; Pharmacy; Plant Sciences; Synthesis; Terpenes; Tryptamines; Tryptophan; diterpenoids; β-carbolines; Pictet–Spengler reaction; heterocyclic compounds; isopimaric acid; XSA
• ISSN: 0009-3130; 1573-8388
• DOI: 10.1007/s10600-019-02836-y

The synthesis and properties of tricyclic pimaranes containing a C-16 β-carboline are reported. A Pictet–Spengler reaction of methyl 15-oxo-16-formylisopimarate (prepared in situ from the 15-oxo-15,16-dihydroisopimarate) and tryptamine or tryptophan methyl ester in the presence of trifluoroacetic acid formed a mixture of terpenoid 1,2,3,4-tetrahydro-β-carbolines, 3,4-dihydro-β-carbolines, and β-carbolines. Tetrahydro- and dihydro-β-carbolines in CHCl
3
were oxidized to the corresponding β-carbolines by treatment in air with basic Al
2
O
3
.