(−)-Frontalin: Synthesis using the Catalytic Enantioselective Addition of Dimethylzinc to a Ketone
作者:Miguel Yus、Diego J. Ramón、Oscar Prieto
DOI:10.1002/ejoc.200300261
日期:2003.8
The first enantioselective synthesis of (−)-frontalin involving an enantioselective nucleophilic 1,2-addition of dimethylzinc to a functionalized α,β-unsaturated ketone, in the presence of titanium tetraisopropoxide and a substoichiometric amount of the chiral ligand 1,2-trans-bis(hydroxycamphorsulfonamido)cyclohexane (HOCSAC, 2) as the key step, is described. The enantiomeric excess is as high as
(-)-frontalin 的第一次对映选择性合成,包括在四异丙醇钛和亚化学计量量的手性配体 1,2-反式存在下,二甲基锌与功能化 α,β-不饱和酮的对映选择性亲核 1,2-加成-双(羟基樟脑磺酰氨基)环己烷 (HOCSAC, 2) 作为关键步骤,进行了描述。对映体过量高达 89%。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)