Diastereoselective addition of monoterpenic alcoholates and thiolates to 2,3-dicarbomethoxynorbornadiene
作者:Ivan Michieletto、Fabrizio Fabris、Ottorino De Lucchi
DOI:10.1016/s0957-4166(00)00231-7
日期:2000.7
Addition of excess lithium salts of (−)-menthol or (−)-borneol to 2,3-dicarbomethoxynorbornadiene 1 affords the transesterification–addition products 4 and 5. The thiols derived from the same monoterpenes give only the addition products to the activated double bond, 6 and 7. In all cases, the addition reaction is totally exo-selective with respect to the norbornadiene moiety and moderately selective
将过量的(-)-薄荷醇或(-)-冰片锂盐添加到2,3-二苯甲氧基降冰片二烯1中可得到酯交换加成产物4和5。衍生自相同单萜的硫醇仅给出活化双键6和7的加成产物。在所有情况下,加成反应是完全外型相对于所述降冰片二烯基-选择性和适度选择性的在区分SI-和重新双键的面取向。两种非对映异构体产物都是C3内-外表位差向异构体的混合物。(-)-薄荷醇与1的主要加成产物 具有已知绝对构型的结晶是晶体,并且具有作为手性配体的前体的潜力。