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. 2018 May 17;3(5):5308-5316.
doi: 10.1021/acsomega.8b00587. eCollection 2018 May 31.

Diastereoselective Synthesis of (±)- epi-Subincanadine C

Manojkumar G Kalshetti  1   2 , Narshinha P Argade  1   2
Affiliations

Diastereoselective Synthesis of (±)- epi-Subincanadine C

Manojkumar G Kalshetti et al. ACS Omega. .

Abstract

Starting from indolylmaleimide, concise and efficient total synthesis of (±)-epi-subincanadine C was described via stereoselective Wittig olefination, base-induced selective mono-prenylation, regioselective Grignard reaction, diastereoselective Pictet-Spengler cyclization, regioselective oxidative carbon-carbon double-bond cleavage, one-pot reductions, and intramolecular cyclization pathway. An attempted synthesis of (±)-subincanadine C via diastereoselective Grignard addition to the α,β-unsaturated γ-lactam or diastereoselective reduction of a carbon-carbon double bond also resulted in yet another route to (±)-epi-subincanadine C.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
Potent cytotoxic alkaloids subincanadines A–G.
Scheme 1
Scheme 1. Concise Retrosynthetic Analysis of (±)-epi-Subincanadine C and (±)-Subincanadine C
Scheme 2
Scheme 2. Synthesis of (±)-epi-Subincanadine C via Diastereoselective Intramolecular Pictet–Spengler Cyclization
Scheme 3
Scheme 3. Attempted Base-Induced Mono-Alkylations
Scheme 4
Scheme 4. Opposite Stereoselections in Michael Addition and Reductions of α,β-Unsaturated γ-Lactams Leading to Exclusive syn-Products: An Attempted Synthesis of (±)-Subincanadine C
See this image and copyright information in PMC

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