Studies in sesquiterpenes—XXII

Natural products inCyperus rotundusL. (Cyperaceae): an update of the chemistry and pharmacological activities

“…Investigation of the constituents from Chinese origin, led to the isolation of known compounds (19,50) and new sesquiterpenes; copadiene (58), epoxyguaien (59), rotundone (60) and 4a,5b-oxidoeudesm-11-en-3a-ol (61). 79,[124][125][126][127] Bioactivity and liquid chromatography-mass spectrometry (LC-MS) guided fractionation of 90% EtOH extract using opencolumn, Sephadex LH-20 and semi-preparative high performance liquid chromatography (HPLC) led to the isolation and identication of thirty-seven sesquiterpenoids. 13 The compounds include, ve new patchoulane-type sesquiterpenoids, 3b-hydroxycyperenoic acid (54), cyperene-3,8-dione (62), 14-hydroxycyperotundone (63), 14-acetoxycyperotundone ( 64 Antimalarial activity-guided investigation and HPLC separation of the crude hexane extract of CR tubers led to the isolation of the sesquiterpenes; 42, patchoulenone (90) and 10,12-peroxycalamenene (91).…”

Biogenetic-Type Rearrangements of Terpenes

“…1~ h"r.' 25° H (195) (37";,) The reaction of either copaene or ylangene, or the corresponding epoxides with protic acids invariably Ieads to ring opening and formation of products related to IX-muurolene (83) or IX-amorphene (84), i. e., the reverse of the biogenetic cyclization (137,(271)(272)(273)(274)(275). Although the trans fused cadinene dihydrochloride is usually isolated from treatment of copaene with anhydrous hydrogen chloride (271)(272)(273), this product may arise from either addition of hydrogen chloride to ö-cadinene (86) or ring juncture isomerization in the subsequent addition of hydrogen chloride to an intermediate muurolene (276).…”

“…Although the trans fused cadinene dihydrochloride is usually isolated from treatment of copaene with anhydrous hydrogen chloride (271)(272)(273), this product may arise from either addition of hydrogen chloride to ö-cadinene (86) or ring juncture isomerization in the subsequent addition of hydrogen chloride to an intermediate muurolene (276). No products resulting from Wagner-Meerwein rearrangement (e.g., copaborneol, ylangoborneol, copacomphene, or sativene) have, as yet, been isolated.…”

Stereoselective Total Synthesis of Copa and Ylango Sesquiterpenoids: Preparation of (−)-(1S,4S,5R,7R)-1,7-Dimethyl-4-isopropylbicyclo[3.2.1]octa-6,8-dione and(+)-(1R,4S,5S,7S)-1,7-Dimethyl-4-isopropylbicyclo[3.2.1]octa-6,8-dione

“…'The terms 'copa' and 'ylango' have by convention been derived from the sesquiterpenoids (-)-a-copaene (6) (I, 2) (structurally related to [1][2][3][4][5], and (+)-a-ylangene (12) (3) (structurally related to [7][8][9][10][11]. On the basis of this structural analysis and system of nomenclature, the more consistent names for sativene (10) and cyclosativene (11) would be ylangocamphene and cycloylangocamphene, respectively.…”