Stemona

Suzuki has explained that the plant from which he isolated stemonine and stemonidine is not, as at first supposed, Stemona japonica Miq. After further investigation it has been named Stemona ovata Nakai and from it he has isolated a third alkaloid, iso stemonidine, m.p. 137°, [a]D — 84-9°, to which the following extended formula has been assigned, Ci 28(NH)(0H),(0—CO)(CO). 

Scheme 21 Threefold use of ruthenium catalysts in the first total synthesis of Stemona alkaloid tuberostemonine (113) [71]...

Several other twofold cyclization strategies have been developed by Smith and coworkers, ultimately to obtain access to the cyclic framework of penitrem D with the correct stereochemistry [176]. Williams group has been interested in Stemona alkaloids, which are represented by approximately 50 structurally novel, polycyclic natu-... 

Quite recently, a domino Diels-Alder/Prins/pinacol reaction was reported by Barriaulfs group [38]. This novel method is very reliable and efficient for the synthesis of highly functionalized bicyclo[m.n.l]alkanones. In addition, Aube and coworker [39] used a combination of a Diels-Alder and a Schmidt reaction within the total synthesis of the Stemona alkaloid stenine [40]. 

In the synthesis of the azabicyclic core of the Stemona alkaloids, methyl (2/W,3.9/ ,3a/W)-2-(2-cthoxycarbonylethyl)-hexahydropyrrolo[l,2- ]isoxazole-3-carboxylate was hydrogenolyzed over 10% Pd-C in EtOAc and acetic acid at room temperature to give after cyclization the bicyclic lactam 153 <2005JOC3157> (Equation 22). This route was also used to produce pyrrozilidinone-based dipeptide isosteres <2005T8836>. 

Stemona japonica (BI.) Miq. S. tubemsa Lour. Bai Bu Dei Ye Bei Bu (root) Stemonine, isotemonidine, stemonidine, protostemonine.33 50 Suppress excitation of the respiratory center and inhibit the cough reflex. Antitubercular, antibacterial, antifugal. 

Stemona tuberosa Lour Lepidium apetalum Willd. 

Aconitum barbatum, A. austroyunnanense, Stemona japonica, S. tuberosa... 

Zi Wan (Asteris radixj, Kuan Dong Hua (Tussilaginis farfarae) and Bai Bu (Stemonae radix,)... 

The genus Stemona is the source of insecticidal principles alkaloids have been reported from Stemona and Croomia. Three species of Stemona S. australiana, S. sessilifolia, and S. luberosa) gave positive tests the last two were known earlier. 

Several isoxazolidines or their quaternary salts derived from the 1,3-dipolar cycloaddition of rr/i-hcxcnolidcs (6,7-dihydrooxepin-2(5//)-ones) to cyclic nitrones, were converted into the corresponding piperidyl- and pyrrolidyloxepi-nones by reduction of the nitrogen-oxygen bond (Equation 4). These amino alcohols provide a new access to the l-azabicyclo[5.3.0]decane core of the Stemona alkaloids <2004EJ04215>. 

An interesting approach toward the total synthesis of the Stemona alkaloid, (-)-stenine (25), which have been used in Chinese and Japanese folk medicine as insecticides, as drugs for the treatment of respiratory diseases, via spirolactone... 

TMS)3SiH-mediated 7-ewdo-trig cyclization of bromides was employed as the key step for the construction of the azepinoindole tricyclic core of the Stemona alkaloid94. 

Stemoamide (36), isolated from the roots and rhizomes of Stemona tuberosa in 1992, is one of the structurally simplest members of the Stemona family and has shown many biological activities. Olivo and others used a highly... 

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