An Efficient, Stereocontrolled Synthesis of a Potent Omuralide−Salinosporin Hybrid for Selective Proteasome Inhibition
作者:Leleti Rajender Reddy、Jean-François Fournier、B. V. Subba Reddy、E. J. Corey
DOI:10.1021/ja052376o
日期:2005.6.1
analysis. Acrylamide 7 was cyclized to 8 by a novel application of the Kulinkovich Ti(II)-cyclopentene complex. Silylation of 8 to 9 and radical cyclization at low temperature produced the bicyclic lactam 10 with complete control of all stereocenters. Hydroxy desilylation and N-deprotection of 10 gave the dihydroxy ester 11, which was converted to 3 by a novel three-step sequence: (1) demethylation with
已经开发了从 (S)-苏氨酸衍生的恶唑啉 4 中短时间和高度立体控制的合成蛋白酶体抑制剂 3。合成顺序总结在方案 1 中。4 的烯醇酸锌与异丁醛的羟醛偶联和随后的甲硅烷基化以非对映选择性 (10:1) 提供 TBS 醚 5。将 5 的恶唑啉环还原裂解,然后对所得氨基醇进行 Swern 氧化,得到氨基酮 6,通过 N-酰化进一步转化为丙烯酰胺 7,其结构通过 X 射线晶体学分析得到证实。通过 Kulinkovich Ti(II)-环戊烯配合物的新应用,丙烯酰胺 7 环化为 8。8 到 9 的硅烷化和低温下的自由基环化产生双环内酰胺 10,完全控制所有立体中心。