Fragment 6 of thiazolyl peptide GE 2270 D2 and fragment 11 of dolabellin were synthesized stereoselectively from 2,4-dibromothiazole (1) in three (6, 44% overall yield) and five synthetic steps (11, 63% overall yield). Key to the success of the strategy was a bromine-magnesium exchange, which proceeds with excellent regio- and chemoselectivity at carbon atom C-2 of 1.
氮
硫噻唑肽GE 2270 D2的片段6和多拉别林的片段11是从
2,4-二溴噻唑(1)中以立体选择性合成的,合成分别经历了三步(6,整体产率44%)和五步(11,整体产率63%)。该策略成功的关键在于
溴-
镁位交换,该反应在1的C-2碳原子上具有优异的区域选择性和
化学选择性。