1,7‐Cyclogermacra‐1(10),4‐dien‐15‐al, a sesquiterpene with a novel skeleton, and other sesquiterpenes from Haitian vetiver oil

A medium polar part of commercial Haitian vetiver oil was investigated, particularly with regard to carbonyl compounds. The following new natural compounds were characterized by their NMR data: 1,7‐cyclogermacra‐1(10),4‐dien‐15‐al ( 1 ); 10‐ epi ‐acor‐3‐en‐5‐one ( 3 ); 10‐ epi ‐acora‐3,11‐dien‐15‐al ( 4 ); ( E )‐opposita‐4(15),7(11)‐dien‐12‐al ( 6 ); 13‐ nor ‐opposit‐4(15)‐en‐11‐one ( 8 ); 7‐ epi ‐ cis ‐dracunculifoliol (ax‐4(15)‐en‐7‐ol, 11 ); elema‐1,11‐dien‐15‐al (2 epimers, 12a,b ); 6,12‐epoxyelema‐1,3‐diene ( 14 ); eremophila‐1(10), 6‐dien‐12‐al (2 epimers, 15a,b ); 15‐ nor ‐funebran‐3‐one ( 24 ); 7,15‐epoxyprezizaane ( 31 ); 15‐ nor ‐prezizaan‐7‐one ( 33 ); 12‐ nor ‐preziza‐7(15)‐en‐2‐one ( 35 , presumable structure); prezizaan‐15‐al ( 46 ); cyclocopacamphan‐12‐al (2 epimers, 57a,b ); 5,6‐ seco ‐6,7‐furoeudesman‐5‐one ( 59 ); 11,12,13‐tri‐ nor ‐ cis ‐eudesm‐5‐en‐7‐one ( 61a ); 11,12,13‐tri‐ nor ‐ cis ‐eudesma‐5,8‐dien‐7‐one ( 62 ); 13‐ nor ‐eudesm‐5‐en‐11‐one (2 epimers, 63a,b ); and 13‐ nor ‐ trans ‐eudesma‐4(15),7‐dien‐11‐one ( 67 ). Two oxiranes, 13‐ nor ‐4,5‐epoxyeudesm‐6‐en‐11‐one ( 66 ) and 13‐ nor ‐7,8‐epoxy‐ trans ‐eudesm‐4(15)‐en‐11‐one ( 68 ), which were also isolated, might be artefacts. The polar part of the oil was converted to the methyl ethers. Distillative and chromatographic separation furnished, among others, β‐funebrenyl methyl ether 23′ , prezizaenyl methyl ether 50′ , khusimyl methyl ether 51′ , and cyclocopacamphanyl methyl ethers 58a′,b′ (epimers). Thus, the existence of the new alcohols β‐funebren‐14‐ol ( 23 ) and prezizaen‐12‐ol ( 50 ) was established. The formerly described configurations of the prezizaane derivatives jinkohol, jinkohol II and jinkoholic acid are formulated as the 2‐ epi ‐compounds 45 , 48 and 49 . Copyright © 2000 John Wiley & Sons, Ltd.