Asymmetric Vinylogous Mukaiyama Aldol And Vinylogous Mukaiyama Michael Reaction Based On2-(Trimethylsilyloxy)Furan

Butenolide derivatives are a very important class of biologically active molecules, of which the butenolide structural subunit is widely present in the natural products. Owing to their significant biological activity, the development of efficient catalytic methods for the generation of optically active butenolides has attracted considerable attention. This dissertation is divided into two parts and an efficient asymmetric synthesis method for builting butenolide moiety is presented in each part.In the first part of this dissertation, the recent progress on asymmetric synthesis of a-hydroxy phosphonates has been summarized and a series of C2-symmetric chiral bis(oxazoline) ligands (BOX) were evaluated for the synthesis of optically active a-hydroxy phosphonates containing butenolide block. Other factors were also examed, such as solvent, temperature and additives. Finally, the asymmetric vinylogous Mukaiyama aldol reaction between a-keto phosphonate and2-(trimethylsilyloxy)furan (TMSOF) was performed by using CH2i’Pr-BOX-CuⅡ complexes as the catalyst and2,2,2-trifluoroethanol (TFE) as additive in CH2Cl2at-78℃. The present method was highly tolerable for functionalized a-keto phosphonate and giving the corresponding quaternary a-hydroxy phosphonates in high yields (up to86%) and good to excellent enantio-and diastereoselectivities (up to98%ee,99:1dr).In the second part of this dissertation, the recent progress on vinylogous Mukaiyama Michael reaction involving alkylidene malonates has been reviewed. Meanwhile we also systematically studied the reaction between2-(trimethylsilyloxy)furan (TMSOF) and alkylidene malonates. The Michael reaction between TMSOF and alkylidene malonates underwent smoothly in the presence of5mol%Zn(OTf)2in ether at0℃and resulted into Michael adducts in high yields with moderate diastereoselectivities (up to93%yield,91:9dr).