Clovenes

Revision Problem 5 This molecule (TM 400) was used by Raphael in his synthesis of the natural product clovene. How could you make it. 

Clove leaf oil Clove oils Clover Cloven te Cloves... 

Technology Description Hydrolysis is the process of breaking a bond in a molecule (which is ordinarily not water-soluble) so that it will go into ionic solution with water. Hydrolysis can be achieved by the addition of chemicals (e.g., acid hydrolysis), by irradiation (e.g., photolysis) or by biological action (e.g., enzymatic bond cleavage). The cloven molecule can then be further treated by other means to reduce toxicity. 

The formation of an enamine from an a,a-disubstituted cyclopentanone and its reaction with methyl acrylate was used in a synthesis of clovene (JOS). In a synthetic route to aspidospermine, a cyclic enamine reacted with methyl acrylate to form an imonium salt, which regenerated a new cyclic enamine and allowed a subsequent internal enamine acylation reaction (309,310). The required cyclic enamine could not be obtained in this instance by base isomerization of the allylic amine precursor, but was obtained by mercuric acetate oxidation of its reduction product. Condensation of a dihydronaphthalene carboxylic ester with an enamine has also been reported (311). 

When caryophyllene alcohol is dehydrated by means of zinc chloride or phosphorus pentoxide, a hydrocarbon results, which does not appear to be identical with any of the sesquiterpenes described under the name caryophyllene. It has therefore been named clovene . Clovene has the following characters —... 

It is normally found in parts of Europe, Africa, Asia, and South America. The natural reservoirs are wild and domestic cloven-footed animals. It is one of the most contagious diseases of these animals. Airborne spread is possible up to 40 miles over land and 180 miles over water. It can survive for up to 2 weeks in dry fecal material and for 6 months in slurry, about 1 week in urine, and over 3 months in hay. 

Reactions in which a reagent is cloven (i) The termination reactions of the type (IX) in which an anionic fragment is abstracted from the anion, so that the chain-carrier is neutralised. This type of termination has been claimed to occur in many systems for example, in the polymerization of tetrahydrofuran by PF5 a terminal F from PF 6 was indeed found [119]. 

This alkynone thermolysis has served as the key step in several natural product syntheses. The considerations that lead to regio- and stereochemical control are illustrated by an elegant synthesis of clovene 725. Thermolysis of the symmetrical alkynone 4 could lead to three different enones, two of which (5 and 6) arc illustrated. In fact, only 8-methyltricyclo[8.3.1.01 5]dodec-3-en-2-one (5) is isolated, in 80% yield. The structure of 5 was confirmed by straightforward conversion to the tricyclic hydrocarbon clovene. The outcome of the thermolysis was anticipated, as it had previously been observed that C-H insertion is most facile when the intermediate alkylidene can achieve coplanarity with the target C-H bond. In this system, such coplanarity is achievable only via the boat conformation of one of the two symmetrical rings. 

Copper, of fine quality, free from torrefied, crumbling, or cloven masses. 

Like other deer (family Cervidae), moose have cloven hooves, and are therefore in the mammalian order Artiodactyla. Moose are the largest animals in the deer family, weighing as much as 1,750 lb (800 kg) and standing as tall as about 6.6 ft (2 m). The laiggest moose... 

Some of the most remarkable transannular cyclizations have been uncovered during the treatment of natural caryophyllene (63) with mineral acids. Thus, treatment of (63) with concentrated sulfuric acid has been shown to lead to a mixture of clovene (62), caryolan-l-ol (64) and neoclovene (65 ... 

Intramolecular C—insertion is, essentially, a method for specific remote functionalization of hydrocarbons. An important implication of this for synthetic strategy is that the C—H insertion process can dissolve symmetry, thus leading from a simple precursor to a much more complex product. Both the clovene synthesis, by Dreiding, and the pentalenolactone E synthesis, by Cane, take advantage of this idea. It is further illustrated by the pentalenolactone E synthesis reported by Taber (Scheme 1). In the key step, P-keto ester (139), which has a single stereogenic center, is transformed into the tricyclic ketone (140), which has four stereogenic centers. 

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