cis,cis-Spiro[4.4]nonane-1,6-diol: A new chiral auxiliary for the asymmetric Diels-Alder reaction
作者:James A. Nieman、Brian A. Keay
DOI:10.1016/s0957-4166(96)00459-4
日期:1996.12
The use of a mono-pivalate mono-acrylate bis-ester of (+)-1S,5S,6S-spiro[4.4]nonane-1,6-diol in an asymmetric Diels-Alder reaction with cyclopentadiene (2 equiv. BCl3, −85°C, CH2Cl2) provided the expected endo bicyclo adduct in >97% de. Iodolactonization of the bicyclo adduct provided the (+)-lactone (5) with a 1S,4S,6S,8R,9S configuration (97% ee). The de's obtained from using various types and amounts
(+)-1 S,5 S,6 S-螺[4.4]壬烷-1,6-二醇的单新戊酸酯单丙烯酸酯双酯在与环戊二烯的不对称Diels-Alder反应中的应用(2当量BCl 3,-85℃,CH 2 Cl 2)提供了预期的内环双环加合物,其> 97%de。双环加合物的碘内酯化为(+)-内酯(5)提供1 S,4 S,6 S,8 R,9 S配置(97%ee)。还报道了通过使用各种类型和数量的路易斯酸获得的de's,以及Diels-Alder与环戊二烯的反应中的手性和外消旋双酯。