Cavicularin is a phenolic secondary metabolite isolated from the liverwort Cavicularia densa. This macrocycle is unusual because it was the first compound isolated from nature displaying optical activity due to the presence of planar chirality and axial chirality. The optical rotation for (+)-cavicularin is +168.2° ^[1]. It is also a very strained molecule. It incorporates an arene moiety that adopts a boat conformation with an C-C-C bond angle of 15°. For comparison, an unstrained benzene ring is flat with all carbon bond angles zero. This type of angle strain in aromatic compounds is normally reserved for synthetic cyclophanes. Phenol, also known under the old name carbolic acid, is a colorless crystalline solid with a typical sweet tarry odor. ... Secondary metabolites, also known as natural products, are those products (chemical compounds) of metabolism that are not essential for normal growth, development or reproduction of an organism. ... Orders Need to be entered Liverworts are non-vascular plants in the Class Marchantiopsida, formerly known as the Hepaticae. ... When polarized light is passed through a substance containing chiral molecules (or nonchiral molecules arranged asymmetrically), the direction of polarization can be changed. ... Planar chirality is a special case of chirality in which a molecule does not posess a asymmetric chiral carbon atom but perpendicular disymmetric planes due to restricted rotation around a chemical bond in the molecule. ... Term used to refer to stereoisomerism resulting from the non-planar arrangement of four groups in pairs about a chirality axis. ... When polarized light is passed through a substance containing chiral molecules (or nonchiral molecules arranged asymmetrically), the direction of polarization can be changed. ... In chemistry a molecule experiences strain when in a chemical conformation there exist unfavorable bond angles or bond distances. ... Arene or Ar means several things: Another term for aromatic hydrocarbon In Greek mythology, Arene was the wife of Aphareus and mother of Idas and Lynceus. ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... Benzene, C6H6, PhH, or benzol is a colorless and flammable liquid with a pleasant, sweet smell. ... The presence of angle strain in a molecule indicates that in a specific chemical conformation there exists a bond angle that deviates from the bond angle required to archieve maximum bond strength. ...

The liverwort was obtained from Mt. Ishizuchi in the district of Shikoku. The material is dried for one day, ground to a powder and 5 gram was refluxed in methanol for 4 months (!) to yield 2.5 mg (0.049%) of cavicularin after column chromatography and preparative TLC. Fortunately in 2005 the compound was prepared by total synthesis together with the unstrained compound riccardin C ^[2]. cavicularin File links The following pages link to this file: Cavicularin Categories: User-created public domain images ... Orders Need to be entered Liverworts are non-vascular plants in the Class Marchantiopsida, formerly known as the Hepaticae. ... Shikoku (四国, four lands, often incorrectly translated as provinces) is the smallest and least populous of the four main islands of Japan. ... Reflux is a technique used in chemistry to apply energy to reactions over an extended period of time. ... Methanol, also known as methyl alcohol or wood alcohol, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid that is used as an antifreeze, solvent, fuel, and as a denaturant for ethyl alcohol. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ... A total synthesis is the complete chemical synthesis of complex organic molecules from simple, commercially available (petrochemical) precursors. ...

Riccardin C File links The following pages link to this file: Cavicularin Categories: User-created public domain images ...

References

• ^[1] (+)-Cavicularin: A Novel Optically Active Cyclic Bibenzyl-Dihydrophenanthrene Derivative from the Liverwort Cavicularia densa Steph. M. Toyota, T. Yoshida, Y. Kan, S. Takaoka, Y. Asakawa Tetrahedron letters 1996 4745-4748 Abstract (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THS-3V99257-14&_user=1065764&_handle=V-WA-A-W-CD-MsSAYVA-UUA-U-AAWAUAUZVD-AAAYCEAVVD-AZVWVYEDB-CD-U&_fmt=summary&_coverDate=07%2F01%2F1996&_rdoc=32&_orig=browse&_srch=%23toc%235290%231996%23999629972%2339771!&_cdi=5290&view=c&_acct=C000051225&_version=1&_urlVersion=0&_userid=1065764&md5=4e93161113dd5af8dad768dd3c3d842a)
• ^[2] Total Synthesis of Cavicularin and Riccardin C: Addressing the Synthesis of an Arene That Adopts a Boat Configuration David C. Harrowven, Timothy Woodcock , Peter D. Howes Angewandte Chemie, Volume 44, Issue 25 , Pages 3899 - 3901 2005 Abstract (http://www3.interscience.wiley.com/cgi-bin/abstract/110498256/ABSTRACT)