Chiral arene-Cr(CO)3 complexes in organic synthesis: A short enantioselective total synthesis of putative helioporin D
作者:Thomas Geller、Hans-Günther Schmalz、Jan W. Bats
DOI:10.1016/s0040-4039(98)00021-5
日期:1998.3
The first total synthesis of a member of the helioporin class of marine diterpenes has been achieved. Starting from (4aS)-η6-5,6-dimethoxytetralin-Cr(CO)3 (≥99% e.e.) the target molecule (putative helioporin D) is obtained in a mere 8 steps in an excellent overall yield of 45%. The synthesis is based on the specific reactivity and stereochemistry of the arene-Cr(CO)3 substructure and involves highly
已经完成了海洋二萜类Helioporin类成员的首次全合成。从(图4a开始小号)-η 6 -5,6- dimethoxytetralin铬(CO)3(≥99%ee值)的目标分子(推定helioporin d)是在仅仅8个步骤45%优良的总收率得到。合成是基于芳烃-Cr(CO)3亚结构的特定反应性和立体化学,并且涉及高度区域和非对映选择性的苄基去质子化/烷基化步骤。通过将苄基锂化配合物与原位生成的(R)-6-甲基-5-庚烯-2-醇。通过X射线晶体结构分析确认了烷基化产物的相对构型。由于合成目标化合物的NMR数据与天然Helioporin D的NMR数据不一致,因此必须修改后者的立体结构。