A new synthesis of amino acid-based enantiomerically pure substituted 2,3,4,4a,5,6-hexahydro-1H-pyrazino[1,2-a]quinoxalines
作者:Krishnananda Samanta、Gautam Panda
DOI:10.1039/c000029a
日期:——
A new series of enantiomerically pure 2,3,4,4a,5,6-hexahydro-1H-pyrazino[1,2-a]quinoxalines were synthesized for the first time in twelve steps from 1-fluoro-2-nitrobenzene and S-amino acids with 13–20% overall yields. First use of intramolecular Mitsunobu cyclization for 1,2,3,4-tetrahydroquinoxalines followed by PPh3/I2/imidazole mediated 6-exo-tet cyclization were the key steps.
从12个步骤中首次合成了一系列新的对映体纯的2,3,4,4a,5,6-hexahydro-1 H-吡嗪并[1,2- a ]喹喔啉1-氟-2-硝基苯和S-氨基酸,总产率为13–20%。首次将分子光延环用于1,2,3,4-四氢喹喔啉PPh 3/ I 2 /咪唑 介导的 6-外- TET 环化是关键步骤。