89-31-6Relevant articles and documents
Total synthesis of bernumicine and bernumidine, two alkaloids from Berberis nummularia
Pinet,Chavant,Averbuch-Pouchot,Vallee
, p. 65 - 67 (2007/10/03)
Bernumicine and bernumidine are two alkaloids extracted from Berberis nummularia. Their total synthesis has been completed and it has been shown that the configuration of the stereogenic carbon of both is (R).
Quinolizidines. VIII. Structure and Synthesis of the Alangium Alkaloid Alangicine: Syntheses of (+/-)- and (+)-Alangicines
Fujii, Tozo,Yamada, Koichiro,Minami, Shinzaburo,Yoshifuji, Shigeyuki,Ohba, Masashi
, p. 2583 - 2592 (2007/10/02)
The first total synthesis of alangicine (3), an Alangium lamarckii alkaloid, has been achieved in the form of a racemic modification by means of an initial alkaline hydrolysis of the (+/-)-tricyclic ester 6 and succeeding steps proceeding through the intermediates (+/-)-7, (+/-)-10, and (+/-)-9.A parallel synthetic route starting with the (-)-tricyclic ester 6, derived from (+)-cincholoipon ethyl ester (8), produced the chiral target molecule (+)-3 via the intermediates (-)-7, (-)-10, and 9.The identity of the synthetic (+)-3 with alangicine unequivocally established the structure and absolute stereochemistry of this alkaloid.The (13)C nuclear magnetic resonance spectra of (+/-)-alangicine (3) and the ipecac and Alangium alkaloid psychotrine (18) confirmed their endocyclic double bond structures in the dihydroisoquinoline moiety.Catalytic reductions of 11, (+/-)-12, and 15 using hydrogen and Pd-C were investigated, and the results have shown that hydrogenolysis of the benzyloxy group proceeds much faster than saturation of the endocyclic C=N bond.Keywords - alangicine; psychotrine; structure; absolute configuration; stereoselective synthesis; (13)C NMR; CD; benzyl ether; hydrogenolysis