Enantioselective Synthesis of the Predominant AB Ring System of the <i>Schisandra</i> Nortriterpenoid Natural Products
作者:Birgit Gockel、Shermin S. Goh、Emma J. Puttock、Hannah Baars、Guilhem Chaubet、Edward A. Anderson
DOI:10.1021/ol502027m
日期:2014.9.5
An enantioselective synthesis of the AB ring system common to the majority of the Schisandra nortriterpenoid natural products is reported. Key steps include a stereospecific ring opening of a trisubstituted epoxide and the use of a β-lactone to enable installation of the gem-dimethyl functionality of the B ring. An acetalization strategy played a key role in a late-stage biomimetic AB ring bicyclization
据报道,大多数五味子降冰片五萜天然产物共有的AB环系统的对映选择性合成。关键步骤包括三取代的环氧化物的立体有择的开环,以及使用β-内酯来实现B环的gem- methyl官能团的安装。缩醛化策略在后期仿生AB环双环化中起关键作用。