Cocculus hirsutus

Finally, a sequence consisting of thionium ion formation, thionium ion trapping, an aromatic substitution, and an alkylation, as elaborated by Padwa and coworkers, will be discussed [462]. Since several related sequences have already been mentioned in the foregoing sections, only the total synthesis of ( )-jamtine N-oxide (2-916) will be discussed here (Scheme 2.204). This natural product is an alkaloid from the shrub Cocculus hirsutus, which is commonly found in Pakistan [463]. 

Cocsuline A-oxide (470), C35H34N206, amorphous, mp 182-187°C (MeOH), [a], 5 + 125° (c 0.5, MeOH), was found in Cocculus hirsutus D.C. (Menispermaceae). Sul-furous acid reduction yielded cocsuline (29). The A-oxide appears to be a metabolic product as it was not formed from 29 in vitro under the isolation conditions. It is the first diphenyl ether-linked dibenzodioxin A -Oxide alkaloid and the first A -Oxide from a Cocculus species (557). 

Cocculus hirsutus Cryptocarya alba Liriodendron tulipifera Ocotea sp. (Brazil) ... 

Anisocycla jollyana (Pierre) Diels (Menispermaceae)]235] Cocculus hirsutus Diels (Menispennaceae)(329-331]... 

C24H29NO7 M 443.496 Alkaloid from aerial parts of Cocculus hirsutus (Menispermaceae), [a] +147 (CHCI3). 

Only five alkloids of this type have been described in the literature, all isolated from Cocculus hirsutus. 

In the same way as the hirsutine alkaloids, these alkaloids have only been isolated five times and all of them from Cocculus hirsutus. The five alkaloids were called cohirsine, cohirsitine, cohirsinine, cohirsitinine and shaheenine. The first to be isolated was cohirsine in 1987 (52-53). 

Isolated from Cocculus hirsutus (32, 74), this spiroben ltetrahydro-isoquinolone seems to directly originate, as were the HIRSUTI, COHIRSI and BENZAZE types (see 11,12 and 13 respectively), from a piotoberberine precursor, as can be seen in Scheme 23. 

Ahmad VU, Rahman A, Rasheed T, Rehman H. Jamtine-N-oxide-a new isoquinoline alkaloid from Cocculus hirsutus. Heterocycles 1987 26(5) 1251-1255. 

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