Some limitations of an approach to the assembly of bryostatins by ring-closing metathesis
作者:Raphaël Dumeunier、Thomas Gregson、Somhairle MacCormick、Hiroki Omori、Eric J. Thomas
DOI:10.1039/c7ob00079k
日期:——
Preliminary studies into the use of ring-closing metathesis (RCM) in a convergent approach for the total synthesis of bryostatins are described. An ester that would have provided an advanced intermediate for a synthesis of a 20-deoxybryostatin by a RCM was prepared from an unsaturated acid and alcohol corresponding to the C1–C16 and C17–C27 fragments. However, studies of the formation of the C16–C17
初步研究了闭环复分解(RCM)在融合方法中用于bryostatin的全合成的用途。由不饱和酸和对应于C1-C16和C17-C27片段的醇制备可以为RCM合成20-脱氧bryostatin提供高级中间体的酯。但是,通过RCM对C16-C17双键形成的研究并不成功,并且获得了复杂的产物混合物。为了深入了解该系统中可能阻碍RCM的因素,我们制备了略微简化的C1-C16酸和改性的C17-C25醇,并研究了它们在合成抑菌素类似物中的用途。尽管仅获得了较低的收率,但似乎可以通过RCM制备类似于溴抑他汀的大环内酯类药物,如果前体在C18处缺少两个甲基,则使用Grubbs II催化剂。然而,对于其中存在这些甲基的底物,未观察到RCM。