Bornyl chloride

Present in citronella and valerian oils, tur penline, ginger, rosemary and spike oils. It is produced artificially by the elimination of hydrogen chloride from bornyl chloride (artifi cial camphor) or from isobornyl chloride, by the dehydrogenation of borneol and isobor-neol and by the action of elhanoic anhydride on bornylamine. Chiral. 

Ordinary commercial camphor is (-i-)-cam phor, from the wood of the camphor tree. Cinnamonum camphora. Camphor is of great technical importance, being used in the manufacture of celluloid and explosives, and for medical purposes, /t is manufactured from pinene through bornyl chloride to camphene, which is either directly oxidized to camphor or is hydrated to isoborneol, which is then oxidized to camphor. A large number of camphor derivatives have been prepared, including halogen, nitro and hydroxy derivatives and sulphonic acids. 

It is best prepared, however, by converting the alcohol, borneol, into bomyl chloride. The bornyl chloride is carefully dried and then gently warmed with an equal weight of aniline. The mixture is then heated to the boiling-point of aniline when the reaction, which is suddenly violent, 18 quickly completed. The reaction mass is neutralised by hydrochloric acid and distilled over in a current of steam. Gamphene is rapidly condensed and solidifies to a crystalline mass. 

In the same way bornyl and isobornyl chlorides react with milk of lime. But, whereas bornyl chloride gives an almost quantitative yield of... 

D,L-Ketopinic acid has been prepared by oxidation of bornyl chloride with nitric acid at 20° or with perbenzoic acid in acetic acid from 10,10-dinitrocamphan-2-on or apocamphan-2-ol-l-carboxylic acid with alkaline permanganate and from the oxidation of 10-camphorchlorosulfoxide, obtained from 10-camphorsulfonyl chloride by the action of pyridine, with potassium permanganate. The present procedure represents a simplification of the latter and gives as high an overall yield. ... 

Bornene has been prepared from the reaction of 2-bromo-bornane-3-carboxyIic acid with aqueous sodium bicarbonate,6 by pyrolysis of isoborneol methyl xanthate,7 and by the j8-elimination of hydrogen chloride from bornyl chloride with sodium alkoxides in various solvents.2... 

Wheland (1960) made the point in several ways that these principles could lead to absurd errors. When ethyl chloride is treated with hydroxide ion, we obtain ethanol, not dimethyl ether but when iso-bornyl chloride is treated in the same way we obtain camphene after a deep-seated skeletal rearrangement. Although nucleophilic substitution at an ethylenic center goes with retention (Miller and Yonan, 1957), the Walden inversion undercuts any general principle of minimum configurational change. Likewise, an early PLM representation of the... 

Borneol, camphene, and a-pinene are made in nature from geranyl pyrophosphate. The biosynthesis of a-pinene and the related camphor is described in the chapter. In the laboratory bornyl chloride and camphene can be made from a-pinene by the reactions described below. Give mechanisms for these reactions and say whether you consider them to be biomimetic. 

In the conversion of a-pinene (2.8) into bornyl chloride (2.9) endo isomer), the rearrangement to a 2° carbocation is favoured by relief of small-ring strain (Scheme 2.9). In a similar manner the conversion of camphene hydrochloride (2.10) into isobornyl chloride (2.11) involves rearrangement known as the Wagner-Meerwein rearrangement (Scheme 2.10). 

SYNS BORNANE, 2-CHLORO-, endo- 2-CHLORO-CAMPHANE BICYCLO(2,2,l)HEPTANE, 2-CHLORO-1,7,7-TRIMETHYL-, endo- BORNYL CHLORIDE TERPENE HYDROCHLORIDE TURPENTINE CAMPHOR endo-2-CHLORO-l,7,7-TRIMETHYU BICYCLO(2.2.1)HEPTANE... 

BORNYL CHLORIDE see BMD300 BOROETHANE see DDI450 BOROFAX see BMCOOO BOROFLUORIC ACID see FDD125 BOROFLUORIC ACID see HHS600 BOROHYDRURE de POTASSIUM (FRENCH) see PKY250... 

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