View source for Thujopsene

Thujopsene

{{chembox
| verifiedrevid = 321916171
|   Name = Thujopsene
|   ImageFile1 = thujopsene.png
|   IUPACName = (1aS,4aS,8aS)-2,4a,8,8-tetramethyl-1,1a,4,4a,5,6,7,8-octahydrocyclopropa[d]naphthalene

|   OtherNames = Widdrene
| Section1 = {{Chembox Identifiers
|   SMILES = CC1=CC[C@]3(C)CCC[C@](C)(C)[C@]23C[C@@H]12
|   InChI =1/C15H24/c1-11-6-9-14(4)8-5-7-13(2,3)15(14)10-12(11)15/h6,12H,5,7-10H2,1-4H3/t12-,14-,15-/m0/s1
| InChIKey = WXQGPFZDVCRBME-QEJZJMRPBP
| PubChem = 442402
| CASNo = 470-40-6 
| ChemSpiderID=390845
  }}
| Section2 = {{Chembox Properties
|   Formula = C<sub>15</sub>H<sub>24</sub>
|   MolarMass = 204.35 g/mol
|   Appearance = Clear, colourless liquid
|   Density = 0.936 g/mL (liquid at 20°C)
|   Solubility = Very low
|   BoilingPtC = 258-260
|   SpecRotation = &minus;110° (CHCl<sub>3</sub>)
  }}
| Section7 = {{Chembox Hazards
|   MainHazards = flammable
|   FlashPt = 104 °C
|   NFPA-H = 0
|   NFPA-F = 1
|   NFPA-R = 0
  }}
| Section8 = {{Chembox Related
|   Function = alkene
|   OtherFunctn = [[Cedrene]], [[Germacrene]]
|   OtherCpds = [[Cedrol]], [[Widdrol]]
  }}
}}
'''Thujopsene''' is a tricyclic [[sesquiterpene]] commonly found in oils isolated from trees of the [[Cupressaceae]] (cypress) family, especially the geni ''[[Thujopsis]]'', ''[[Juniperus]]'' (juniper) and ''[[Widdringtonia]]''.  Thujopsene has a sweet smell of pencil wood<ref name="Carreira2009">{{cite book|last1=Carreira|first1=Erick M.|last2=Kvaerno|first2=Lisbet|title=Classics in Stereoselective Synthesis|url=http://books.google.com/books?id=Wxs75BuoULgC&lpg=PA494&ots=RF48VeLunS&dq=Synthesis%20of%20thujopsene&pg=PA494#v=onepage&q=Synthesis%20of%20thujopsene&f=false|accessdate=Aug 17, 2010|year=2009|publisher=Wiley|location=New York|isbn=978-3-527-29966-9|page=494}}</ref>, and it undergoes acetylation with rearrangement to produce a compound with a woody odour which is used for perfumery.

==Structure==
The correct structure and relative stereochemistry (''cis'') was first established in 1961 by T. Norin, <ref name="Norin1961">{{cite journal|last=Norin|first=Torbjörn|year=1961|title=The Chemistry of the Natural Order Cupressales. 40. The Structure of Thujopsene and Hinokiic Acid.|journal=[[Acta Chemica Scandinavica]]|volume=15|pages=1676–1694|url=http://actachemscand.dk/volume.php?select1=3&vol=15|language=English|doi=10.3891/acta.chem.scand.15-1676 }}</ref> and confirmed by total synthesis in 1963.<ref name="Dauben1963">{{cite journal|last=Dauben|first=William G.|coauthors=Arnold C. Ashcraft|year=1963|title=The Total Synthesis of (±)-Thujopsene|journal=Journal of the American Chemical Society|volume=85|pages=3673–3676|doi=10.1021/ja00905a032}}</ref>.  The absolute configuration was established by T. Norin in 1963,<ref name="Norin1963">{{cite journal|last=Norin|first=Torbjörn|year=1963|title=The Chemistry of the Natural Order Cupressales. 49. The Configuration of Thujopsene.|journal=Acta Chemica Scandinavica|volume=17|pages=738–748|doi=10.3891/acta.chem.scand.17-0738|url=http://actachemscand.dk/volume.php?select1=3&vol=17|language=English}}</ref> confirming work on the related sesquiterpene [[widdrol]] by C. Enzell. <ref name="Enzell1962">{{cite journal|last=Enzell|first=C.|year=1962|title=The Chemistry of the Natural Order Cupressales. 47. The Structures and Absolute Configurations of Widdrol and Widdrol-alpha-epoxide.|journal=Acta Chemica Scandinavica|volume=16|pages=1553–1568|doi=10.3891/acta.chem.scand.16-1553|url=http://actachemscand.dk/volume.php?select1=3&vol=16|language=English}}</ref>

==Occurrence==
Thujopsene is the principal component in several natural ''Cupressacea'' oils.  It was first isolated from ''[[Thujopsis dolabrata|hiba oil]]'' by Yano (1913) and Uchida (1928)<ref name="Johnson1982">{{cite journal|last=Johnson|first=Carl R.|coauthors=Michael R. Barbachyn|year=1982|title=β-Hydroxysulfoximine-Directed Simmons-Smith Cyclopropanations. Synthesis of (-)- and (+)-Thujopsene|journal=Journal of the American Chemical Society|volume=104|pages=4290–4291|doi=10.1021/ja00379a060}}</ref> .  It was given the name ''thujopsene'' in 1930 by Kawamura, who assigned an incorrect structure based on a homologue of [[alpha-pinene]].<ref name="Akiyoshi1957">{{cite journal|last=Akiyoshi|first=Saburo|coauthors=Nagahama, Shizuo|year=1957|title=Polyterpenes I. Permanganate Oxidation of Thujopsene, Part 1|journal=Bulletin of the Chemical Society of Japan|volume=30|pages=886–889|doi=10.1246/bcsj.30.886|url=http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=bcsj1926&cdvol=30&noissue=8&startpage=886|language=English}}</ref>

In 1958, thujopsene was identified (initially as "widdrene") in the [[heartwood]] of the five ''[[Widdringtonia]]'' species by Erdtman and Thomas. <ref name="Erdtman1958">{{cite journal|last=Erdtman|first=H.|coauthors=B. R. Thomas|year=1958|title=The Chemistry of Natural Order Cupressales. XX. Heartwood Constituents of the Genus Widdringtonia.|journal=Acta Chemica Scandinavica|volume=12|pages=267–273|doi=10.3891/acta.chem.scand.12-0267|url=http://actachemscand.dk/volume.php?select1=2&vol=12|language=English}}</ref>   Thujopsene was then identified as the principal volatile component in the essential oil from various other species, including ''[[Juniperus cedrus]]'' and [[Juniperus phoenicea]]; in 1960 Runeburg commented that "''J. Phoenicea'' appears to be the most convenient source of thujopsene so far encountered."<ref name="Runeburg1960e">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXXI. Constituents of ''Juniperus phoenicea L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1995-1998|doi=10.3891/acta.chem.scand.14-1995|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>  It is also a significant component (around 30%) of the misnamed"[[cedar oil]]", isolated from ''[[Juniperus virginiana]]'' (Easter redcedar), which has been produced in very large quantities for the perfumery industry.<ref name="Runeburg1960b">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXVIII. Constituents of ''Juniperus virginiana L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1288–1294|doi=10.3891/acta.chem.scand.14-1288|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>

Thujopsene content in various types of wood is given in Table 1.  The total % oil indicates what percentage of the wood was isolated as an essential oil.  Note that thujopsene does not occur in significant quantities in ''[[Juniperis procera]]<ref name="Pettersson1961">{{cite journal|last=Pettersson|first=E.|coauthors=Runeburg, Jarl|year=1961|title=The Chemistry of the Natural Order Cupressales XXXIV. Constituents of ''Juniperus procera'' Hochst. and ''[[Juniperus californica'' Carr.|journal=Acta Chemica Scandinavica|volume=15|pages=713-720|doi=10.3891/acta.chem.scand.15-713|url=http://actachemscand.dk/volume.php?select1=3&vol=15}}</ref> or ''[[Juniperus foetidissima]]''. <ref name="Runeburg1961a">{{cite journal|last=Runeburg|first=Jarl|year=1961|title=The Chemistry of the Natural Order Cupressales XXXIV. Constituents of ''Juniperus foetidissima'' Willd.|journal=Acta Chemica Scandinavica|volume=15|pages=721-726|doi=10.3891/acta.chem.scand.15-721|url=http://actachemscand.dk/volume.php?select1=3&vol=15}}</ref>  All figures are approximate and variable.
{| class="wikitable sortable"
|+'''Thujopsene content in dry wood'''  
|-
! Species !! Common name !! % Thujopsene<br/> in dry wood !! % Thujopsene<br/>in distilled oil !! Ref. 
|-
| ''[[Juniperis chinensis]]''
|  Chinese juniper
| 0.27
| 
| <ref name="Pilo1960">{{cite journal|last=Pilo|first=Claes|coauthors=Runeburg, Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXV.  Heartwood constituents of  ''Juniperis chinensis L.''|journal=Acta Chemica Scandinavica|volume=14|pages=353–358|doi=10.3891/acta.chem.scand.14-0353|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus osteosperma]]''
|  Utah juniper
| 0.18
| 19*
| <ref name="Runeburg1960a">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXVII. Heartwood constituents of  ''Juniperus utahensis Lemm.''|journal=Acta Chemica Scandinavica|volume=14|pages=797–804|doi=10.3891/acta.chem.scand.14-0797|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus virginiana]]''
|  Eastern Redcedar
| -
| 30†
| <ref name="Runeburg1960b">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXVIII. Constituents of ''Juniperus virginiana L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1288–1294|doi=10.3891/acta.chem.scand.14-1288|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus thurifera]]''
|  Spanish Juniper
| 0.4
| -
| <ref name="Runeburg1960c">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXIX. Constituents of ''Juniperus thurifera L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1985–1990|doi=10.3891/acta.chem.scand.14-1985|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus cedrus]]''
|  Canary Islands Juniper
| 2.2
| -
| <ref name="Runeburg1960d">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXX. Constituents of ''Juniperus cedrus L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1991-1994|doi=10.3891/acta.chem.scand.14-1991|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus phoenicea]]''
|  Arâr
| 2.2
| -
| <ref name="Runeburg1960e">{{cite journal|last=Runeburg|first=Jarl|year=1960|title=The Chemistry of the Natural Order Cupressales XXXI. Constituents of ''Juniperus phoenicea L.''|journal=Acta Chemica Scandinavica|volume=14|pages=1995-1998|doi=10.3891/acta.chem.scand.14-1995|url=http://actachemscand.dk/volume.php?select1=3&vol=14}}</ref>
|-
| ''[[Juniperus californica]]''
|  California Juniper
| 0.1
| -
| <ref name="Pettersson1961">{{cite journal|last=Pettersson|first=E.|coauthors=Runeburg, Jarl|year=1961|title=The Chemistry of the Natural Order Cupressales XXXIV. Constituents of ''Juniperus procera'' Hochst. and ''[[Juniperus californica'' Carr.|journal=Acta Chemica Scandinavica|volume=15|pages=713-720|doi=10.3891/acta.chem.scand.15-713|url=http://actachemscand.dk/volume.php?select1=3&vol=15}}</ref>
|}
<small>* Percentage in only the neutral oil portion isolated via an acetone extraction; excludes the portion that is extractable into base.<br/>† Percentage in the oil obtained by steam distillation.</small>

==Biosynthesis==
The commonly accepted biosynthesis<ref name="Mann1994">{{cite book|last1=Mann|first1=J.|last2=Davidson|first2=R.S.|last3=Hobbs|first3=J.B.|coauthors=Banthorpe, D.V.; Harborne, J.B.|title=Natural Products: their chemistry and biological significance|year=1994|publisher=Longman|location=Harlow, Essex, UK|language=English|isbn=0-582-06009-5|pages=319-320}}</ref> begins with ''2Z,6E''-[[farnesyl pyrophosphate]] (FPP) or its allylic isomer, nerolidyl pyrophosphate.  These starting materials can both produce an allylic ion that cyclises to [[Bisabolol|bisabolene]].  Bisabolene then (after reprotonation) cyclises further to form a seven-membered ring; this may simply hydrate (forming [[widdrol]]), or it may cyclize again, forming the three membered ring system of thujopsene.

[[File:ThujopseneBiosynthesis.png|600px|center|Biosynthesis of thujopsene from FPP]]

Bisabolene is also invoked as an intermediate in the related biosyntheses of [[Juvabione#Biosynthesis_of_.28.2B.29-juvabione_and_.28.2B.29-todomatuic_acid| juvabione]], [[cedrene]] and [[cuparene]].

==Laboratory synthesis==
Dauben's early synthesis of thujopsene was critical in defining the relative stereochemistry, confirming Norin's proposed ''cis'' structure.

The first laboratory total synthesis of enantiomerically pure (&minus;)-thujopsene was by Johnson and Barbychyn in 1982, and this also used a Simmons-Smith approach, this time involving a chiral auxiliary.

==Chemical and biochemical reactions==
Thujopsene can easily undergo [[autoxidation]] to [[mayurone]] in high yield in the presence of a cobalt(II) dioxan complex.<ref name="Ito1972">{{cite journal|last=Ito|first=Masaaki|coauthors=Nishimura, Terumi; Abe, Kazuo|year=1972|title=The Autocatalytic Oxidation of Thujopsene. A Facile Synthesis of Mayurone|journal=Bulletin of the Chemical Society of Japan|volume=45|pages=1914–1915|doi=10.1246/bcsj.45.1914|url=http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=bcsj1926&cdvol=45&noissue=6&startpage=1914|language=English}}</ref>; this conversion can also be accomplished using [[potassium permanganate]] or [[potassium dichromate]].<ref name="Akiyoshi1957">{{cite journal|last=Akiyoshi|first=Saburo|coauthors=Nagahama, Shizuo|year=1957|title=Polyterpenes I. Permanganate Oxidation of Thujopsene, Part 1|journal=Bulletin of the Chemical Society of Japan|volume=30|pages=886–889|doi=10.1246/bcsj.30.886|url=http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=bcsj1926&cdvol=30&noissue=8&startpage=886|language=English}}</ref>

==References==
{{Reflist}}

[[Category:Natural products]]
[[Category:Sesquiterpenes]]