Synthesis of the hasubanan ring system from the alkaloid reticuline

Intramolecular oxidative coupling of diphenolic, monophenolic, and nonphenolic substrates

“…The reaction mixture was cooled to -60 °C in a dry ice-acetone bath, 71 mg (0.42 mmol) of AgNÜ3 was added, and stirring was continued at -60 °C for 30 min. The temperature was then raised to 80 °C and stirring was continued for 15 min, after which time the initial white suspension had turned black. The reaction mixture was acidified with HC1, the solids were removed by filtration, and the filtrate was extracted with ether.…”

Alkaloids

“…The structures of hasubanonine (209) and cepharamine (210) have been derived by the use of physical methods on the degradation products [204]. The structure of the related, novel halogen-containing alkaloid acutuminine (211) was proposed on the basis of spectra and confirmed by X-ray analysis [205].…”

“…(±)-Cepharamine (210) and (±)-hasubanonine (209) have been synthesized via Robinson annelation [206], [207]. Photolytic and phenolic oxidative methods have been used to synthesize hasubanan alkaloids [208], [209].…”

“…Photolytic and phenolic oxidative methods have been used to synthesize hasubanan alkaloids [208], [209]. …”

Substrate-Modified Functional Group Reactivity: Hasubanan and Acutumine Alkaloid Syntheses

“…Our synthetic efforts culminated in syntheses of 10 hasubanan and two acutumine alkaloids, including the namesake alkaloids (−)-hasubanonine (19) and (−)-acutumine (47). We first reported syntheses of four hasubanan alkaloids (19,22,30, and 31) 1 and later adapted our synthetic strategy to syntheses of the acutumine alkaloids 47 and 48. we described the syntheses of six additional hasubanan alkaloids (23−26, 28, and 29). 3 This latter manuscript also includes a full account of our work, 3 and so a detailed presentation is not duplicated here.…”