Stereochemistry of Epoxidation of Some Caryophyllenols.
Epoxidation of the caryophyllene allylic alcohols 3-5 by tert-butyl hydroperoxide/vanadyl acetylacetonate afforded the epoxides 6a, 7, and 8, respectively. The tetracyanoethylene-catalyzed solvolysis shed some light on the stereochemistry of epoxidation. Formation of trans epoxides by syn epoxidation is a consequence of the conformational flexibility of the nine-membered ring, which places the alcohol at C-5 close to the alpha-face of the endo-alkene in 4 and close to the beta-face in 3 and 5.
Collado
Isidro G.
IG
Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, Apartado 40, 11510 Puerto Real, Cádiz, Spain, and The School of Chemistry and Molecular Sciences, University of Sussex, Brighton BN1 9QJ, Great Britain.
Hanson
James R.
JR
Hitchcock
Peter B.
PB
Macías-Sánchez
Antonio J.
AJ