476-33-5Relevant academic research and scientific papers
Stereoselective total synthesis of (±)-homochelidonine
Yoshida, Makoto,Watanabe, Toshiko,Ishikawa, Tsutomu
, p. 6751 - 6753 (2002)
(±)-Homochelidonine, a B/C-cis-11-hydroxyhexahydrobenzo[c]phenanthridine alkaloid, was stereoselectively synthesized from arnottin II, a non-alkaloidal spirolactonyl tetralone which had been structurally correlated to chelerythrine, a fully aromatized-type alkaloid, by the common use of a 2-benzofuranyl-1-tetralone as a synthetic key intermediate. Thus, a valuable synthetic method accessible to benzo[c]phenanthridine alkaloids with different oxidation stages of the basic skeleton could be proposed.
Concise enantioselective total syntheses of (+)-homochelidonine, (+)-chelamidine, (+)-chelidonine, (+)-chelamine and (+)-norchelidonine by a PdII-catalyzed ring-opening strategy
Fleming, Matthew J.,McManus, Helen A.,Rudolph, Alena,Chan, Walter H.,Ruiz, Jeremy,Dockendorff, Chris,Lautens, Mark
experimental part, p. 2112 - 2124 (2009/04/06)
New enantioselective syntheses of the B/C hexahydrobenzo[c]phenanthridine alkaloids (+)-homochelidonine, (+)-chelamidine, (+)-chelidonine, (+)-chelamine, and (+)-norchelidonine are described. Our rapid and convergent route to this class of natural products involved the development and application of a Pd II-catalyzed asymmetric ring-opening reaction of a mesoazabicyclic alkene with an aryl boronic acid as the key step. By screening a variety of functionalized ortho-substituted aryl boronic acids, chiral ligands and reaction conditions we were able to prepare the requisite cis-1-amino-2- aryldihydronaphthalenes in high yield and in up to 90% ee. Early attempts to complete the synthesis of (+)-homochelidonine using an N-Boc azabicyclic alkene are described in full. The successful route required a protecting group alteration followed by B ring for-mation and then stereoselective installation of the C-11 syn-hydroxy group by regioselective epoxide ring-opening using a hydride source. Ring-opening of the same epoxide intermediate with water ultimately led to the synthesis of (+)-chelamidine. The same strategy was then used to synthesize the other structurally similar B/C hexahydrobenzo[c] phenanthridine alkaloids, (+)-chelidonine, (+)-chelamidine, and (+)norchelidonine.
Enantioselective total synthesis of (+)-homochelidonine by a Pd II-catalyzed asymmetric ring-opening reaction of a meso-azabicyclic alkene with an aryl boronic acid
McManus, Helen A.,Fleming, Matthew J.,Lautens, Mark
, p. 433 - 436 (2008/02/02)
(Chemical Equation Presented) An efficient and highly convergent enantioselective synthesis of (+)-homochelidonine has been achieved (see scheme; Cbz = benzyloxycarbonyl, MOM = methoxymethyl) and relied on a new and powerful desymmetrizing ring-opening reaction of a meso-azabicycle with an aryl boronic acid. The route should allow access to other hexahydrobenzo[c]phenanthridine alkaloids.
Photocyclisation of Enamides. Part 19. Total Synthesis of (+/-)-Homochelidonine
Ninomiya, Ichiya,Yamamoto, Okiko,Naito, Takeaki
, p. 2171 - 2174 (2007/10/02)
Photocyclisation of the enamide (2) and successive stereoselective functionalisation of the photocyclised didehydro lactam (3a) completed the first total synthesis of (+/-)-homochelidonine (7e).
