Synthesis of (R, S)-[2,3-13C2]-1-(1′-methyl-2′-pyrrolidinyl)propan-2-one; {(R, S)-[2′,3′-13C2]hygrine}
作者:Timothy W. Abraham、Edward Leete
DOI:10.1002/(sici)1099-1344(199605)38:5<419::aid-jlcr859>3.0.co;2-l
日期:1996.5
give (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-5'-oxo-2'-pyrrolidinyl)propan-2-one (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H + ), followed by reduction of the amide to the amine using LiAlH 4 and subsequent deprotection of the ketal gave (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one ((R,S)-[2',3'- 13 C 2 ]Hygrine) (8) in 78% yield. (61% overall yield from ethyl
2-乙氧基-1-甲基-5-吡咯烷酮(1)与[3,4- 13 C 2 ]-乙酰乙酸乙酯(2)在TiCl 4 存在下反应得到[3,4- 13 C 2 ]乙酯-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutanoate (3),产率为 85%。[3,4- 13 C 2 ] -2-(1'-甲基-5'-氧代-2'-吡咯烷基)-3-氧代丁酸乙酯 (3) 的脱碳乙氧基化使用 NaCl 和 H 2 O 在 DMSO 中完成,得到(R,S)-[2,3- 13 C 2 ]-1-(1'-甲基-5'-氧代-2'-吡咯烷基)丙-2-一 (4),产率为 91%。将酮保护为缩酮(乙二醇,H + ),然后使用 LiAlH 4 将酰胺还原为胺,随后将缩酮脱保护得到 (R,S)-[2,3- 13 C 2 ]- 1-(1'-甲基-2'-吡咯烷基)propan-2-one ((R,S)-[2'