Development of a Merged Conjugate Addition/Oxidative Coupling Sequence. Application to the Enantioselective Total Synthesis of Metacycloprodigiosin and Prodigiosin R1

We report the enantioselective total syntheses of mavacurans alkaloids, (+)-taberdivarine H, (+)-16-hydoxymethyl-pleiocarpamine, (+)-16-epi-pleiocarpamine, and their postulated biosynthetic precursor 16-formyl-pleiocarpamine. This family of monoterpene indole alkaloids is a target of choice since some of its members are subunits of intricate bisindole alkaloids such as bipleiophylline. Inspired by the biosynthetic hypothesis, we explored an oxidative coupling approach from the geissoschizine framework to form the N1-C16 bond. Quaternization of the aliphatic nitrogen was key to achieve the oxidative coupling induced by KHMDS/I2 since it hides the nucleophilicity of the aliphatic nitrogen and locks the required cis conformation.

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Enantioselective Total Synthesis of atrans-Hydrindane Rings/Side-Chain Building-Block of Vitamin D− Asymmetric Induction in an Acid-Catalyzed Conjugate-Addition Reaction

European Journal of Organic Chemistry ◽

10.1002/ejoc.200300611 ◽

2004 ◽

Vol 2004 (4) ◽

pp. 783-799 ◽

Cited By ~ 11

Author(s):

Evgueni Gorobets ◽

Viatcheslav Stepanenko ◽

Jerzy Wicha

Keyword(s):

Vitamin D ◽

Total Synthesis ◽

Building Block ◽

Addition Reaction ◽

Conjugate Addition ◽

Asymmetric Induction ◽

Side Chain ◽

Enantioselective Total Synthesis ◽

Acid Catalyzed

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Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for the Enantioselective Total Synthesis of Mavacuran Alkaloids

10.26434/chemrxiv.8046938 ◽

2019 ◽

Author(s):

Maxime Jarret ◽

Victor Turpin ◽

Aurélien Tap ◽

Jean-Francois Gallard ◽

Cyrille Kouklovsky ◽

...

Keyword(s):

Total Synthesis ◽

Oxidative Coupling ◽

Indole Alkaloids ◽

Oxidative Cyclization ◽

Total Syntheses ◽

Enantioselective Total Synthesis ◽

Biosynthetic Precursor ◽

Monoterpene Indole Alkaloids ◽

Coupling Approach

We report the enantioselective total syntheses of mavacurans alkaloids, (+)-taberdivarine H, (+)-16-hydoxymethyl-pleiocarpamine, (+)-16-epi-pleiocarpamine, and their postulated biosynthetic precursor 16-formyl-pleiocarpamine. This family of monoterpene indole alkaloids is a target of choice since some of its members are subunits of intricate bisindole alkaloids such as bipleiophylline. Inspired by the biosynthetic hypothesis, we explored an oxidative coupling approach from the geissoschizine framework to form the N1-C16 bond. Quaternization of the aliphatic nitrogen was key to achieve the oxidative coupling induced by KHMDS/I2 since it hides the nucleophilicity of the aliphatic nitrogen and locks the required cis conformation.

Download Full-text