Structures of kokzeylanol and kokzeylanonol two new natural tri- and tetra- oxygenated D:A-friedo-oleananes
✍ Scribed by A.A.Leslie Gunatilaka; N.P.Dhammika Nanayakkara; M. Uvais; S. Sultanbawa
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- French
- Weight
- 200 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
Kokzeylanol and kokzeylanonol obtained from Kokoona zeylanica have been shown to be 6p,27-dihydroxy-D:A-friedo-olean-3-one ct) and 6/8,27-dihydroxy-D:A-friedo-oleana-3,21-dione Q), respectively by the deoxygenation of their 27-acetoxy derivatives using Lithium-ethylene diamine reduction coupled with spectroscopic and irradiation methods. Kokzeylanonol represents the first tetraoxygenated D:A-friedo-oleanane isolated from a natural source. Recent reports from this laboratory dealt with the application of an irradiation method' and triphenyl tinhydride deoxygenation of the derived thiobenzoates 2 in the structure elucidation of some novel 27-hydroxy-D:A-friedo-olean-21-ones and 6&hydroxy-D:A-friedo-oleananes isolated from Kokoona zeylanica Thwaites (Celastraceae).
We herein report the application of