Tetrahedron p. 5471 - 5484 (1998)
Update date:2022-08-04
Topics: Synthetic studies Fluorinated analogues Asymmetric syntheses Enantiomeric
Kaneko, Satoru
Yoshino, Toshiharu
Katoh, Tadashi
Terashima, Shiro
Syntheses of an enantiomeric pair of huperzine A were accomplished by employing two types of methods which feature the tandem Cinchona alkaloids- promoted asymmetric Michael addition / aldol reaction of the β-keto ester 3 with methacrolein (4) (max. 64% ee, 3+4 → 5, Scheme 2) and the asymmetric bicycloannulation of 3 with 2-methylene-1,3-propanediol diocetate (7) catalyzed by palladium catalysts carrying chiral ferrocenylphosphine ligands (max. 64% ee, 3+7 → 8, Scheme 3) as the key steps. Recrystallization of the partially optically active tricycles (+)- and (-)-6 derived from the products of the asymmetric reactions, readily provided the corresponding optically pure samples (both >99% ee). According to the reported method, the total synthesis of an enantiomeric pair of 1 [(-)- and (+)-1] was completed starting with optically pure (+)- and (-)-6 (Scheme 4).
View MoreXi'an Kaixiang Photoelectric Technology Co., Ltd
website:http://www.kxmaterials.com/
Contact:86-29-15991651477
Address:Building 6, Biopharmaceutical Industry R&D Cluster Base, No. 16, Caotang 4th Road, Caotang Science and Technology Industrial Base, High-tech Zone, Xi'an City, Shaanxi Province, China
ZHEJIANG JIANYE CHEMICAL CO.,LTD.
Contact:86-571-64149273,64149234
Address:No. 48, Fuxi Road, Meicheng Town
Contact:+86-20-32051076
Address:1105,Building A, International Business Incubator,Science City
website:http://www.synchemie.com/
Contact:+86-574-87642758
Address:Room 901, Yinyi Bund Building, 132 Renmin Road
Contact:86-15972077575
Address:changzhou
Doi:10.1016/j.bmcl.2018.01.043
(2018)Doi:10.1002/jhet.1769
(2014)Doi:10.1021/jm00108a007
(1991)Doi:10.1021/ja205345e
(2011)Doi:10.1002/jhet.5570270740
(1990)Doi:10.1055/s-0034-1380419
(2015)