Enantioselective, Organocatalytic Strategy for the Oxazolomycin Core: Formal Synthesis of (+)-Neooxazolomycin
Enantioselective, Organocatalytic Strategy for the Oxazolomycin Core: Formal Synthesis of (+)-Neooxazolomycin
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DOI：
10.1021/acs.orglett.0c03511
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发表时间：
2020-12-04
期刊：
影响因子：
5.2
通讯作者：
Romo, Daniel
中科院分区：
文献类型：
--
作者：
Chaheine, Christian M.;Gladen, Paul T.;Romo, Daniel
一个简洁的，有机催化的，对映选择性路线的γ-内酰胺核心的恶唑霉素的开发。关键步骤包括刘易斯碱催化的Michael质子转移-内酰胺化有机级联、一锅法N-甲基化和非对映选择性α-烷基化、非对映异构基团选择性还原、底物导向的烯丙基羟基化和镧系元素介导的有机锂加成以附加侧链。通过拦截Kende中间体，在10个步骤（以前从α-D-葡萄糖24个步骤）中获得的（+）-新恶唑霉素的正式合成，能够确认相对和绝对立体化学。
A concise, organocatalytic, enantioselective route to the gamma-Iactam core of the oxazolomycins was developed. Key steps include a Lewis base-catalyzed, Michael proton transfer-lactamization organocascade, a one-pot N-methylation and diastereoselective alpha-alkylation, a diastereotopic group-selective reduction, a substrate-directed allylic hydroxylation, and a lanthanide-mediated organolithium addition to append the side chain. A formal synthesis of (+)-neooxazolomycin via interception of a Kende intermediate, accessed in 10 steps (previously 24 steps from alpha-D-glucose), enabled confirmation of the relative and absolute stereochemistry.