Synthesis 2023; 55(15): 2319-2324
DOI: 10.1055/s-0042-1751413
paper
Special Issue dedicated to Prof. David A. Evans

Synthesis of Guaipyridine Alkaloids Rupestine M and L by Cycloaddition/Cycloreversion of an Intermediate 1,4-Oxazinone

Jonathan R. Scheerer
,
Ella B. Leeth
,
Jennifer A. Sprow
This work was supported by the National Institutes of Health (National Institute of General Medical Sciences, R15GM107702 to J.R.S.).


Abstract

A new method to prepare 1,4-oxazinone intermediates was developed based on aza-conjugate addition of β-amino alcohols to electron-deficient alkyne precursors. A tandem intramolecular cycloaddition/cycloreversion reaction sequence was evaluated, leading to the synthesis of the guaipyridine alkaloid natural products rupestine M and L. Starting from (–)-citronellal and thus a known configuration of the C5 stereocenter, a revised absolute configuration of natural rupestine L is suggested based on optical rotation.

Supporting Information



Publication History

Received: 11 November 2022

Accepted after revision: 04 January 2023

Article published online:
02 February 2023

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