Total syntheses of (±)-α-acorenol, β-acorenol, α-epi-acorenol and β-epi-acorenol via an Ireland ester Claisen rearrangement and RCM reaction sequence

Natural sesquiterpenoids

“…118 Racemic total syntheses of a-acorenol, b-acorenol, a-epi-acorenol and b-epiacorenol have been accomplished. 119 The cedrane derivative 134 has been obtained from the wood of Juniperus lucayana. 115 Essential oils from the roots of Vetiveria nigritana 120 afforded the new sesquiterpenes cedren-15-oic acid 135, 2-epi-prezizanoic acid 136, negritene 137 and dehydronegritene 138.…”

Scalable and Divergent Total Synthesis of (+)-Colletoic Acid, a Selective 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor

“…To demonstrate the versatility of our synthetic strategy, compound 9c was converted to its corresponding methyl ester compound 9d , therefore completing a formal total synthesis of α/β acorenol and α/β epi -acorenol natural products (Scheme ) …”

Total syntheses of natural products containing spirocarbocycles

“…The acoranes are a group of highly-oxygenated sesquiterpenes containing a spiro [4.5] core. They have been isolated from a variety of sources, [31][32][33] including sweet flag Acorus calamus, the essential oils of the woods of Juniperus rigida and J. chinensis, and Australian sandalwood oil from Santalum spicatum. (±)-Acorone was synthesised in 1977 by the Dolby group, starting from 4-methyl-3-cyclohexene carboxaldehyde and using an intramolecular base-catalysed aldol cyclisation 34 (NaOEt/EtOH).…”

“…The acoranes are a group of highly-oxygenated sesquiterpenes containing a spiro[4.5] core. They have been isolated from a variety of sources, [31][32][33] including sweet flag Acorus calamus, the essential oils of the woods of Juniperus rigida and J. chinensis, and Australian sandalwood oil from Santalum spicatum.…”

“…119,120 4.2 Acoranes: trichoacorenol, α-acorenol, β-acorenol, acorone, isoacorone, acorenone and α-acoradiene Trichoacorenol is a sesquiterpenoid 121 produced by the fungi Trichoderma koningii and T. harzianum. 121,122 The unnatural enantiomers (−)-trichoacorenol and (−)-acorenone have both been synthesised from (+)-(R)-pulegone 122 α-Acorenol and β-acorenol were synthesised starting from cyclohexan-1,4-dione in 7 steps and 67% overall yield 33 by Srikrishna et al in 2007. The key steps were an Ireland-Claisen rearrangement and ring-closing metathesis (Scheme 39).…”