Radical additions onto enols and enol ethers as a stratagem in synthesis. Total synthesis of the unique epoxy-lactone (±)-alliacolide found in Marasmius alliaceus
- 1 January 1988
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 5,p. 1107-1118
- https://doi.org/10.1039/p19880001107
Abstract
The use of intramolecular radical additions onto enols and enol ethers is illustrated in a total synthesis of (±)-alliacolide (3), its methyl ether (39), noralliacolide (25), and several isomeric compounds. The overall strategy for the synthesis of these unique epoxy-lactones is based on (i) spiro-annulation of the tetronic acid ring in the key intermediate (11)via the cyclopentenone (13); (ii) 6-exo-trig radical cyclisation from (11) to the tricycle (10), and (iii) stereocontrolled epoxidation of the β-orientated hydroxy intermediate (10). A novel feature of this synthesis of (±)-alliacolide (3) is the regio- and stereoselective radical cyclisation leading to (10), which introduces three contiguous chiral centres in the correct relative configuration in the tricycle, in a single step.Keywords
This publication has 1 reference indexed in Scilit:
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