Asymmetric Synthesis of a Selective Endothelin A Receptor Antagonist.
作者:Yoshiaki Kato、Kenji Niiyama、Hideki Jona、Shigemitsu Okada、Atsushi Akao、Shouichi Hiraga、Yoshimi Tsuchiya、Koji Tomimoto、Toshiaki Mase
DOI:10.1248/cpb.50.1066
日期:——
An asymmetric synthesis of a selective endothelin A receptor antagonist 1b is described. Asymmetric conjugate addition of aryllithium derived from 18 to the chiral oxazoline 17 followed by hydrolysis afforded 15 in 96% ee via purification as (S)-(-)-1-phenylethylamine salt. Pd(OAc)(2)/dppf (1,1'-bis(diphenylphosphino)ferrocene) catalyzed carbonylation followed by chemoselective addition of aryllithium
描述了选择性内皮素A受体拮抗剂1b的不对称合成。通过纯化将(18)衍生的芳基锂不对称共轭加成到手性恶唑啉17上,然后水解得到96%ee中的15(S)-(-)-1-苯基乙胺盐。Pd(OAc)(2)/ dppf(1,1'-双(二苯基膦基)二茂铁)催化的羰基化反应,然后化学选择性加入衍生自23的芳基锂,得到酮24。非对映选择性地将其与儿茶酚硼烷还原,然后伴随活化所得的醇和环化得到晚期中间体26。通过亚氨基基重排引入吡啶环上的氨基部分,然后脱保护并通过结晶纯化,提供对映体纯的靶分子1b,其从16的总产率为8%。