73554-66-2Relevant articles and documents
Studies on asymmetric total synthesis of (?)-β-hydrastineviaa chiral epoxide ring-opening cascade cyclization strategy
Cheng, Maosheng,Li, Jihui,Liu, Yongxiang,Meng, Jiaxin,Qin, Qiaohua,Song, Xinjing,Wu, Tianxiao,Zhao, Dongmei,Zheng, Yang
, p. 18953 - 18958 (2020/06/08)
Herein, facile and enantioselective approaches to synthesize the core phthalide tetrahydroisoquinoline scaffold of (?)-β-hydrastineviaboth a CF3COOH-catalyzed (86% ee) and KHMDS-catalyzed (78% ee) epoxide ring-opening/transesterification cascade cyclization from chiral epoxide under very mild conditions are described. The key elements include a highly enantioselective epoxidation using the Shi ketone catalyst and an intramolecular CF3COOH-catalyzed cascade cyclization in one pot, and a late-stage C-3′ epimerization under MeOK/MeOH conditions as the key steps to achieve the first total synthesis of (?)-β-hydrastine (up to 81% ee).
Some Reactions of β-Hydrastine
Chatterjee, A.,Bhattacharyya, S.,Bhattacharyya, S.
, p. 74 - 76 (2007/10/02)
β-Hydrastine (I) is an erythro compound, the chiral centres at C-1 and C-9 having R and S configurations respectively.Its conversion into the hitherto unknown threo-isomer by the reduction of the corresponding immonium derivative (II) with zinc and acetic acid has met with failure.Surprisingly, II with Zn/ AcOH regenerates β-hydrastine.During this reduction II rather suffers reductive cleavage yielding the non-nitrogenous lactone, meconine (IV).Sodium borohydride and catalytic reductions of II also fail to afford the threo-isomer.The latter is found to be extremely unstable as revealed from Dreiding model because of the severe steric interaction between the axial hydrogen at C-4 and the C1'-C2'bond.Benzylic oxidation of β-hydrastine (I) with MnO2, instead of producing the desired 4-oxo derivative (VI), gives 6,7-methylenedioxyisoquinoline arising out of cleavage at C1-C9 bond.
Alkaloids of Corydalis incisa Pers. V. The structures of corydalispirone and corydalisol
Nonaka,Nishioka
, p. 294 - 298 (2007/10/04)
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