Campherenone Camphor

The intramolecular version of this [3 -i- 2] process provides an entry into terpenes with a bicy-clo[2.2.1]heptane skeleton. ° Treatment of the Cio dibromo ketone (74) with Fe2(CO)9 produces ( )-camphor in reasonable yield (equation 59). The corresponding C15 analog (75) yields a 2 1 mixture of ( )-campherenone (76) and ( )-epicampherenone (77) (equation 60). The product ratio is reversed if the (Z)-isomer of the dibromo ketone precursor is used. 

As a sequel to the elegant and highly efficient synthesis of camphor by an intramolecular cyclization. Money et have successfully applied this method to the synthesis of the naturally-occurring sesquiterpenoids campherenone (110) and campherenol (111) whose structures and absolute stereochemistries have recently been deduced.In this sequence, dihydrocarvone (112) was readily converted into the keto-ketal (113) from which the homologated chloro-ketone (114) was obtained. Treatment of the corresponding enol acetate (115) with boron trifluoride in wet methylene chloride afforded the two bicyclic chloro-ketones (116) and (117) in 55-60% yield. Conversion of the corresponding iodo-ketals... 

A useful synthesis (ref.ll)of patchouli alcohol, an important fragrant constituent of patchouli oil, from (+)-camphor, that onetime important natural product which was employed as a plasticiser for nitrocellulose (itself a semi-synthetic polymer), was complicated by structural revision of the sesquiterpene alcohol. Dihydrocarvone (14) obtained by saturation of the ring double bond in carvone, a major constituent of oil of spearmint has been employed for two very different sesquiterpenes, the ketone campherenone (15) and the alcohol, occidentalol (16). In the first case an enol acetate was converted to a bicyclic intermediate by earlier established methodology and the route emulated a plausible biogenetic sequence giving racemic campherenone (ref.12) as shown. Any chirality in (14) is apparently lost. 

Calacone, T16 Calamenene, T16 Calarane, T26 Calciferol, T48 Calcorene, T16 Caldariomycin, Y16 Callicarpone, T33 Callitrisic acid, T33 Calodendrolide, T16 Calycanthidine, K26 Calycanthine, K26 Calycotomine, K2 Camphene, Til Camphenilone, Til Campherenone, T28 Campholic acid, A36 Camphonanic acid, T12 Camphor, Til cw-camphoric acid, T12 Camphoronic acid, T12 Camphorquinone, T12 Camphorsulphonic acids, T11-12 Camptothecin, K29 Canallinin, Z8 Canaric acid, T43 Cancentrine, K2 ... 

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