Synthesis of Optically Active N-(4-Hydroxynon-2-enyl)pyrrolidines: Key Building Blocks in the Total Synthesis of Streptomyces coelicolor Butanolide 5 (SCB-5) and Virginiae Butanolide A (VB-A)
作者:Udo Nubbemeyer、Jonas Donges、Sandra Hofmann、Johannes C. Walter、Julia Reichertz、Moritz Brüggemann、Andrea Frank
DOI:10.1055/s-0037-1610770
日期:2021.8
(S)-configured N-propargylprolinol ethers, coupling delivered N-(4-hydroxynon-2-ynyl)prolinol derivatives as mixtures of C4 diastereomers. Resolution of the epimers succeeded after introduction of an (R)-mandelic ester derivative and subsequent HPLC separation. Alternatively, suitable oxidation gave the corresponding alkynyl ketone. Midland reagent controlled diastereoselective reduction afforded a defined configured
从5-甲基己醛和(S)-构型的N-炔丙基脯氨醇醚开始,偶联递送作为C4非对映异构体的混合物的N-(4-羟基壬-2-炔基)脯氨醇衍生物。引入(R)-扁桃酸酯衍生物并随后进行HPLC分离后,差向异构体的拆分成功。或者,适当的氧化得到相应的炔基酮。Midland试剂控制的非对映选择性还原得到定义的构型的炔丙醇,具有高选择性。烯丙醇的LiAlH 4还原和Mosher分析可阐明结构。适当保护的产物用作对映选择性链霉菌的关键中间体 γ-丁内酯信号分子的全合成。