Isothiourea HBTM-2.1 catalyses the Michael addition–lactonisation of 2-aryl and 2-alkenylacetic acids and α,β-unsaturated trichloromethyl ketones. Ring-opening of the resulting dihydropyranones and subsequent alcoholysis of the CCl3 ketone with an excess of methanol gives a range of diesters in high diastereo- and enantioselectivity (up to 95 : 5 dr and >99% ee). Sequential addition of two different
异
硫脲 HBTM-2.1 催化 2-芳基和 2-烯基
乙酸和 α,β-不饱和三
氯甲基酮的迈克尔加成-内酯化。所得二氢
吡喃酮的开环和随后用过量
甲醇对 CCl 3酮进行醇解得到一系列具有高非对映和对映选择性的二酯(高达 95 : 5 dr 和 >99% ee)。将两种不同的亲核试剂依次添加到二氢
吡喃酮上,得到相应的不同取代的二酸衍
生物。