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1. Synthesis of vinca alkaloids and related compounds. Part 102: Simple synthesis and ring transformation of (±)-minovincine. First synthesis of (±)-vincaminine

Author

Csaba Szántay, Károly Vékey, György Kalaus, Lajos Dr Szabo, László Léder, István Greiner, and Mária Kajtár-Peredy

Subjects
Indole test, Chemistry, Stereochemistry, Organic Chemistry, Total synthesis, Ring (chemistry), Biochemistry, Cycloaddition, Enamine, chemistry.chemical_compound, Drug Discovery, Molecule, Epimer, Benzoic acid
Abstract

A molecule with an indole skeleton, containing a latent acrylic ester function—acting as a diene—readily reacted with benzoic acid (4-bromomethylene-5-oxo)hexyl ester that had been built up from pentane-2,4-dione. Dehydration of the enamine and subsequent [4+2] cycloaddition supplied epimers having the d -secoaspidospermane skeleton. These compounds directly or after epimerization gave (±)-minovincine. Oxidative ring transformation of (±)-minovincine under different conditions led to (±)-16-acetyl-16-deethylapovincamine and (±)-vincaminine.

Published
2003
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2. Synthesis of vinca alkaloids and related compounds. Part 101: A new convergent synthetic pathway to build up the aspidospermane skeleton. Simple synthesis of 3-oxovincadifformine and 3-oxominovincine. Attempts to produce 15β-hydroxyvincadifformine

Author

Mária Kajtár-Peredy, György Kalaus, János Éles, Csaba Szántay, István Greiner, Lajos Dr Szabo, and Pál Szabó

Subjects
chemistry.chemical_classification, Indole test, Vinca, biology, Stereochemistry, Organic Chemistry, Skeleton (category theory), biology.organism_classification, Biochemistry, Aldehyde, Cycloaddition, chemistry, Drug Discovery, Molecule, Organic chemistry, Structural unit
Abstract

A molecule with an indole skeleton, containing a latent acrylic ester function—acting as a diene—was produced from Nb-trityl-2-(hydroxy-methyl)-tryptamine and reacted with esters containing an aldehyde or aldehyde-equivalent structural unit, yielding 3-oxo-16,17-dihydro-Δ20-secodin-17-ol type intermediates from which dehydration, followed by [4+2]cycloaddition, furnished 3-oxovincadifformine and 3-oxominovincine. We also wished to apply the method to produce 15β-hydroxyvincadifformine, however, the appearance of a dimeric product with indole skeleton was observed instead of the expected cycloaddition.

Published
2002
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