Chiral Diels–Alder reaction between cyclopentadiene and nitroso derivatives: thermal isomerisation/racemisation of the adducts
作者:Jean-Marc Heuchel、Sébastien Albrecht、Christiane Strehler、Albert Defoin、Céline Tarnus
DOI:10.1016/j.tetasy.2012.09.005
日期:2012.11
Cyclopentadiene nitroso adducts 1a and ent-1a were synthesised in good yields and good enantiomeric excess from chiral chloro-nitroso derivatives 4 and 5 in the d-mannose and d-ribose series, respectively. The thermal racemisation of these adducts occurred below room temperature. Some other chiral Diels–Alder nitroso adducts were prepared in the d-mandelic, l-prolinol and d-O-methylprolinol series
从d-甘露糖和d-核糖系列的手性氯亚硝基衍生物4和5分别以高收率和良好的对映异构体合成环戊二烯亚硝基加合物1a和ent - 1a。这些加合物的热消旋作用发生在室温以下。制备了其他一些手性Diels-Alder亚硝基加合物,分别为d-扁桃,l-脯氨醇和d- O-甲基脯氨醇,并根据N取代对它们进行了热异构化。从ent - 1a提出了手性酰胺基-环戊烯醇(+)- 2b(一种重要的生物有趣化合物的简单前体)的简单合成方法。