Absolute configurations of brominated sesquiterpenes determined by vibrational circular dichroism.
Two brominated sesquiterpenes, majapolene B (1) and acetylmajapolene B (2), isolated from the red algal genus Laurencia were investigated using vibrational circular dichroism (VCD). The ab initio theoretical VCD and IR calculations of 1 and 2 were performed by density functional theory (DFT) using the B3PW91/6-31G(d,p) basis set. The experimental VCD spectra and corresponding population-weighted theoretical VCD spectra were found to be in excellent agreement in CCl(4) solution in the 1800-850 cm(-1) region, which allowed unambiguous determination of the absolute configurations of (-)-1 and (-)-2 as 7S,10S and 7S,10S, respectively.
Division of Biological Sciences, Graduate School of Science, Frontier Research Center for the Post-Genomic Science and Technology, Hokkaido University, Sapporo 001-0021, Japan. kmonde@glyco.sci.hokudai.ac.jp
Kenji
K
Monde
Tohru
T
Taniguchi
Nobuaki
N
Miura
Charles S
CS
Vairappan
Minoru
M
Suzuki
D001966:Bromine / Q000737:chemistry*; D002251:Carbon Tetrachloride / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods*; D044722:Laurencia / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D012717:Sesquiterpenes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D010936:Plant Extracts; D012717:Sesquiterpenes; D002251:Carbon Tetrachloride; D001966:Bromine; D000432:Methanol