Synthesis 2016; 48(13): 2093-2104
DOI: 10.1055/s-0035-1561583
paper
© Georg Thieme Verlag Stuttgart · New York

Concise Total Syntheses of (±)-Joubertiamine, (±)-O-Methyl­joubertiamine, (±)-3′-Methoxy-4′-O-methyljoubertiamine, (±)-Mesembrane, and (±)-Crinane

Mrinal Kanti Das
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India   Email: alakesh@iiserb.ac.in
,
Subhadip De
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India   Email: alakesh@iiserb.ac.in
,
Shubhashish,
Alakesh Bisai*
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India   Email: alakesh@iiserb.ac.in
› Author Affiliations
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Publication History

Received: 26 December 2015

Accepted after revision: 22 February 2016

Publication Date:
18 March 2016 (online)


Abstract

A method to access cis-3a-aryloctahydroindole alkaloids has been developed through a key strategy involving Eschenmoser–Claisen rearrangement of allylalcohol. This approach gives us an opportunity to access the all-carbon quaternary center required for cis-3a-aryloctahydroindole alkaloids. Subsequent simple allylic oxidation of Eschenmoser–Claisen products and synthetic elaborations (reductions/oxidations) enabled the total syntheses of the title compounds to be completed in good yields in a few steps. The strategic viability was further tested in the total syntheses of Amaryllidaceae alkaloids (±)-mesembrane and (±)-crinane. Towards this end, we synthesized advanced intermediate keto-aldehydes from Eschenmoser–Claisen rearrangement products through iodolactonization followed by elaboration involving reduction and oxidation steps.

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