Investigation of the coupling reaction of tetraacetylsecologanin with oxotryptamine and its derivative

Citation
A. Patthy-lukats et al., Investigation of the coupling reaction of tetraacetylsecologanin with oxotryptamine and its derivative, J NAT PROD, 64(8), 2001, pp. 1032-1039
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Agricultural Chemistry","Pharmacology & Toxicology
Journal title
JOURNAL OF NATURAL PRODUCTS
ISSN journal
0163-3864 → ACNP
Volume
64
Issue
8
Year of publication
2001
Pages
1032 - 1039
Database
ISI
SICI code
0163-3864(200108)64:8<1032:IOTCRO>2.0.ZU;2-4
Abstract
The coupling reaction of tetraacetylsecologanin with 2,3-dihydro-2-oxotrypt amine and its N-b-benzyl derivative was investigated. With the benzylated a mine, the reaction was stopped at the tetracyclic ester level, and with the unsubstituted amine it was immediately followed by lactamization. In both cases, the products were formed with high stereoselectivity at C-3, but as an epimeric pair of 7R and 7S in a ratio of 1:3. The bulky benzyl substitue nt at N-4 directed the stereoselectivity at C-3 in favor of the S configura tion. In the nonbenzylated compounds, the reversible coupling reaction is p robably nonstereoselective, but in lactamization the 3R epimer is stericall y favored and faster and gives the final lactam in this configuration. The formation of the spiro compounds may serve as a model reaction in the inter pretation of the stereoselectivity of the coupling reaction of secologanin with tryptamine in the presence of strictosidine synthase.