Temperature-Independent Stereocontrolled [2+2] Cycloaddition. Potential of the 2,4-Pentanediol Tether in Asymmetric Reactions as a Differential Activation Entropy Promoter
作者:Takashi Sugimura、Takahiro Tei、Atsushi Mori、Tadashi Okuyama、Akira Tai
DOI:10.1021/ja993976o
日期:2000.3.1
Chiral and flexible 2,4-pentanediol-tethered cyclopropanation of olefins with a carbenoid derived from a diazo ester to construct three stereogenic centers
2,4-Pentanediol-tethered cyclopropanation of an olefin with an internal carbenoid generated from a diazo ester proceeded smoothly to give a chiral adduct having three stereogenic centers under full stereocontrol. The high stereoselectivity was not affected by the structure of the olefinic portion, studied so far with six substrates. Conversion of the product cyclopropane to other optically active compounds