Sesquiterpene lactones fromArtemisia barrelieri

Synthesis of Natural Oxygenated Monocarbocyclic Sesquiterpenoids from 6,7-Epoxygeranyl Acetate

“…n-Butyl lithium (2.26 M in hexane, 11.3 ml, 2.94 mmol) and 5.2 ml of HMPA, was added to a solution of 17 (0.83 g, 2.82 mmol) in 30 ml of THF at 2788C, and the whole mixture was slowly warmed to 08C and stirred for 1 h. A solution of allyl bromide (3.41 g, 0.028 mol) was added at 2788C to this mixture and stirred for 12 h. After addition of sat. NH 4 Cl the mixture was diluted with ether (100 ml), washed with 5% HCl, water, sat. NaHCO 3 , and sat.…”

“…A 1 M solution of vinylmagnesium bromide in THF (0.95 ml) was added to a stirred solution of 22 (0.15 g, 0.63 mmol) in THF (4 ml) at 08C, and the whole was stirred at 108C for 20 min, and then quenched with sat. NH 4 Cl. The mixture was extracted with ether (3£15 ml) and the combined extracts were washed with sat.…”

“…farnesiferol C (1) 1 or a cyclohexanol moiety, e.g. achilleol A (2) 2 and farnesiferol B (3) and D (4). 1 During the last few years the isolation of several monocarbocyclic compounds, such as 5, 7, 8 3,4 and elegansidiol (6), 5 have been reported, which suggests that they could be more prevalent than it was presumed.…”

“…7 The present authors have reported the preparation of the same bicyclic ether system by selective electrophilic cyclization of 6,7-epoxygeranyl acetate (9); as well as the obtention of cyclohexanol type structures, such as elegansidiol (6), by the Lewis acid-mediated opening of the bicyclic ether. 5,8 In this paper the synthesis of 5, 7 and 8, natural sesquiterpenes isolated from Artemisia species, 3,4 and elegansidiol (6), a constituent from Santolina elegans, 5 via selective electrophilic cyclization of 6,7-epoxygeranyl acetate (9) is reported.…”

Fragrant Volatile Sesquiterpenoids Isolated from the Essential Oil of Laggera pterodonta by Using Olfactory‐Guided Fractionation

“…The known sesquiterpenoids isolated from the woody-note fraction of the essential oil of L. pterodonta were identified as bisabolol oxide B (2) [12], ylangenol (3) [13], (4) [14], guai-11-en-10-ol (5) [15], spathulenol (6) [16], aromadendran-10-ol (7) [17], caryophyllenol (8) [18], 5a,7a-eudesm-11(13)-en-4a-ol (9) [19], g-costic acid (10) [20], and eudesma-4(15),11(13)-dien-12,5b-olide (11) [21] by comparision of their NMR and MS data with those reported in literature.…”