New Germacranolides From Artemisia herba alba. X-Ray Crystal Structures of 3β,8α-Dihydroxy-6βH, 7αH, 11βH-Germacran-4(14),9(10)-Dien-6,12-Olide and the Corresponding 3-Oxo-Olide

Journal of Natural Products
1981.0

Abstract

The three new germacranolides 3/3,&~-dihydroxy-6pH,7aH,llpH-germacran-4(14),9 (10)-dien-F,12-olide (lo), the corresponding 3-oxo-olide (8) and la-hydroxy-6pH,7aH,llaH-germacran-4 (5) ,10 (15)-dien-6,12-olide (9), together with 2,6,10 t rime thyl-cis-7,10-0xido-dodeca-3E, 1 l-dien-2-01-5one (7), obtained as a natural product for the first time, and thymol were isolated from the ethanol extract of Artemism herba alba from the Sinai desert. The structures of germacranolides 8 and 10 R-ere confirmed by single crystal X-ray analyses. Germacranolide 9 was shown to be the C-11 epimer of the previously reported gallicin. On preparative gas chromatography 9was transformed into eudesmanolide 11. The C-11 epimer of 11 has been previously prepared by treatment of gallicin with hydrochloric acid. Eudesmanolide 11 has been recently reported as a natural product.

Knowledge Graph

Similar Paper