Cavicularin

Cavicularin is a natural phenolic

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norma ...

isolated from the

liverwort The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ...

'' Cavicularia densa''. This

macrocycle Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. ...

is unusual because it was the first compound isolated from nature displaying optical activity solely due to the presence of

planar chirality Planar chirality, also known as 2D chirality, is the special case of chirality for two dimensions. Most fundamentally, planar chirality is a mathematical term, finding use in chemistry, physics and related physical sciences, for example, in astrono ...

and axial chirality. The specific rotation for (+)-cavicularin is +168.2°. It is also a very strained molecule. The ''para''-substituted phenol ring is bent about 15° out of planarity, adopting a somewhat boat-like geometry. This type of

angle strain In organic chemistry, ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are ...

in aromatic compounds is normally reserved for synthetic

cyclophane In organic chemistry, a cyclophane is a hydrocarbon consisting of an aromatic unit (typically a benzene ring) and a chain that forms a bridge between two non-adjacent positions of the aromatic ring. More complex derivatives with multiple aromati ...

s. The

was obtained from

Mount Ishizuchi is a mountain on the border of Saijō and Kumakōgen, in Ehime, Japan. This mountain is one of the 100 famous mountains in Japan. It is the highest mountain in Western Japan and the island of Shikoku. Outline Mount Ishizuchi is the high ...

in the district of

Shikoku is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), '' ...

. The material was dried for one day, ground to a powder and 5 grams were

reflux Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations. It is also used in chemistry to supply energy to reactions ...

ed in methanol for 4 months ^{'reference needed''/sup> to yield 2.5 mg (0.049%) of cavicularin after column chromatography
Column chromatography in chemistry is a chromatography method used to isolate a single chemical compound from a mixture. Chromatography is able to separate substances based on differential adsorption of compounds to the adsorbent; compounds move th ...
and preparative TLC.

Total synthesis

In 2005 and again in 2011, the compound was prepared by total synthesis

Total synthesis is the complete chemical synthesis of a complex molecule, often a natural product, from simple, commercially-available precursors. It usually refers to a process not involving the aid of biological processes, which distinguishes i ...
together with the unstrained compound riccardin C. In 2013, several other syntheses were reported for it and a racemic synthesis.

References

{{Phenanthrenes

Dihydrostilbenoids
Phenanthrenoids
Macrocycles
Diphenyl ethers
Total synthesis
Cyclophanes}