- Enantioselective synthesis of (+)-α-vetivone through the Michael reaction of chiral imines
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(+)-α-Vetivone has been synthesised in nine steps. The absolute stereochemistry of the two stereogenic centres is controlled in the same key step involving the stereoselective Michael addition of a chiral imine of 4-isopropylidene-2-methylcyclohexanone to phenyl crotonate.
- Revial, Gilbert,Jabin, Ivan,Pfau, Michel
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p. 4975 - 4983
(2007/10/03)
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- Synthetic Study of (+)-Nootkatone from (-)-β-Pinene
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A facile stereoselective synthesis of (+)-nootkatone (1) has been achieved starting with (+)-nopinone (2b).The key step was the conjugate addition of methallyltrimethylsilane (20b) to trans-3-ethylidenenopinone (16), which was obtainable from 2b on the cross condensation with acetaldehyde followed by acid treatment, giving an adduct with the desired stereochemistry, 24a, as the predominant product.Dione 23, obtained from the adduct on methylation followed by ozonization, afforded nootkatone hydrochloride (26) on treatment with hydrogen chloride.Regioselective dehydrochlorination of the hydrochloride yielded 1.An alternative route in which allyltrimethylsilane was used is also described.
- Yanami, Tetsuji,Miyashita, Masaaki,Yoshikoshi, Akira
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p. 607 - 612
(2007/10/02)
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