用不对称双羟化反应合成紫杉醇手性中间体(2R,3S)-2-3-二羟基-3-苯基丙酸乙酯

目的设计、合成一种便宜的手性配体(QN)2PYDZ],考察其在不对称双羟化反应(AD)中的催化活性和立体选择性,以期获得低成本、高化学产率和高光学产率的(2R,3S)-2,3-二羟基-3-苯基丙酸乙酯。方法以便宜的3,6-二氯哒嗪为原料合成手性配体,并应用于六种不同底物的AD反应中。结果用简便的方法成功地合成了便宜的(QN)2PYDZ,并发现在催化AD反应中表现出了良好的催化性能。结论用手性配体(QN)2PYDZ催化AD反应可获得高化学产率(90%)和高光学产率(99%)的紫杉醇C13片段的前体(2R,3S)-2,3-二羟基-3-苯基丙酸乙酯,且成本很低,适用性强。

Preparation of ethyl(2R,3S)-dihydroxy-3-phenylpropinate as intermediate of taxoi by asymmetric dihydroxylation reaction

OBJECTIVE To synthesize a cheap ligand and determine it's catalytic activities in asymmetric dihydroxylation(AD)reaction and to get ethyl-(2R,3S)-dihydroxy-3-phenylpropionate with high yield and enantioselectivity.METHODS The new chiral ligand (QN)_2PYDZ was synthesized by cheap material 3,6-dichoropyridazine,which was applied to AD reaction of six olefins. RESULTS The ligand was obtained with lower cost by convenient process,which had satisfying catalytic activities in AD reaction.CONCLUSION The ligand (QN)_2PYDZ can be used to prepare ethyl-(2R,3S)-dihydroxy-3-phenylpropionate with high yield (90%) and enantioselectivity (99%),a precursor of C_ 13 side chain of taxol and the process is economical and adaptable.