Chromatographic and Spectroscopic Data of All Stereoisomers of Eudesm-11-en-4-ol

Essential Oils of Five Baccharis Species: Investigations on the Chemical Composition and Biological Activities

“…The proton and carbon NMR spectra of the two isolates were recorded using an Agilent DD2-500 NMR spectrometer (Agilent, Santa Clara, CA) equipped with a One NMR probe operating at 499.79 MHz for 1 H and 125.67 MHz for 13 C. The spectrum of spathulenol was identical to that of the reference standard. The spectral data of isolated kongol was also in agreement with that reported in the literature [ 52 ].…”

Volatile Constituents of the Rhizomes ofAframomum alboviolaceum (Ridley) K. Schum. from Guinea-Bissau

“…A number of synthetic approaches to the stereoisomers of eudesm-11-en-4-ol have been explored. Wijnberg et al, 18 described the total synthesis of (+)-intermedeol from a racemic mixture of (4aaY 8aa)-hexahydro-4a-methyl-1(2H ),7(8H)-naphthalenedione, but the two enantiomers of intermedeol thus obtained were not separated. The stereoselective synthesis of ()-intermedeol from a starting material of known absolute con®guration (10-epi-eudesma-4,11-dien-3-one) was achieved by Human et al 29 and the (4S, 5S, 7R, 10S) con®guration was assigned.…”

Extern nach Ideen suchen

“…Scheme for carbon numbering of the eudesmane skeleton) ranges from δ =18.3 to δ =18.7 ppm for all of the trans ‐fused structures intermedeol ( 13 ), paradisiol ( 14 ), neointermedeol ( 15 ), and eudesma‐11‐en‐4α‐ol ( 16 ), but is found in the range of δ =28.9 to δ =30.7 ppm for all of the cis ‐fused eudesmane sesquiterpenoids 7‐ epi ‐amiteol ( 17 ), 5‐ epi ‐paradisiol ( 18 ), 5‐ epi ‐neointermedeol ( 19 ), and amiteol ( 20 , Table 2). 23 For the trans ‐eudesmane alcohols, the chemical shift of C‐15 is around 22.4 ppm for 13 and 16 and around 30.0 ppm for 14 and 15 ; this, together with the coinciding signals of C‐12, established the structure of X as that of eudesma‐11‐en‐4α‐ol ( 16 ).…”

“…A eudesmane‐type alcohol X was also tentatively identified from its mass spectrum, but because of contradictory retention index literature data none of the eight possible stereoisomers could be assigned to X . In one systematic study the retention indices of all eight stereoisomers on a DB‐1 column were reported (summarized in Scheme );23 they suggest that one of the isomers 13 , 16 , 17 , or 19 might represent X ( I =1654 on a HP‐5MS column), but these data were not sufficient for unambiguous structural assignment. Furthermore, an oxidized sesquiterpene ( I =1757) with a molecular ion at m / z 218 and a mass spectrum almost identical to that of neopetasone ( I =173324) was tentatively identified as an epimer of this compound.…”

“… The eight possible diastereomers of eudesmane‐type alcohol X . Retention index literature data on a DB‐1 column are given in brackets 23…”