Abstract
The asymmetric total synthesis of epoxyquinols A, B, and C, and epoxytwinol A, and computational analysis of the key biomimetic oxidative dimerization, are described. In the first-generation synthesis, the HfCl4-mediated diastereoselective Diels-Alder reaction of furan with chiral acrylate has been developed. In the second-generation synthesis, a chromatography-free preparation of an iodolactone by using acryloyl chloride as the dienophile in the Diels-Alder reaction of furan, and the lipase-mediated kinetic resolution of a cyclohexenol derivative have been developed. A biomimetic cascade reaction involving oxidation, 6π-electrocyclization, and Diels-Alder dimerization or formal [4 + 4] cycloaddition, is the key reaction in the formation of heptacyclic structure of epoxyquinols A, B, and C, and epoxytwinol A. Intermolecular hydrogen-bonding is found to be the key, causing formation of both epoxyquinols A and B. In the dimerization of epoxyquinol monomer, two monomeric 2H-pyrans interact each other to afford pre-associated complexes stabilized by hydrogen-bonding, then Diels-Alder reaction proceeds.
Original language | English |
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Pages (from-to) | 102-113 |
Number of pages | 12 |
Journal | Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry |
Volume | 67 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2009 Feb |
Keywords
- DFT analysis
- Diels-Alder reaction
- Epoxyquinols A-C
- Epoxytwinol A
- Hafnium tetrachloride
- Lipase-mediated kinetic resolution
- Oxidative dimerization
ASJC Scopus subject areas
- Organic Chemistry