Further insight into the asymmetric vinylogous Mukaiyama aldol reaction (VMAR); application to the synthesis of the C27–C45 segment of lagunamide A
作者:Brent A. Banasik、Lee Wang、Arielle Kanner、B. Mikael Bergdahl
DOI:10.1016/j.tet.2016.03.079
日期:2016.5
C37, C38 and C39, of the southern hemisphere of lagunamide A. The VMAR methodology allows straightforward access of enantiomerically pure material of the essential segment via seven steps, and in an overall yield of 34%. The synthesis has an orthogonal protecting group strategy, essential for upcoming synthesis for completion of lagunamide A. We also demonstrate that steric bulk of the chiral oxazolidinone
为了选择性地在Lagunamide A的南半球C37,C38和C39处安装三个连续的立体中心,已应用了两个迭代的乙烯基Mukaiyama羟醛反应(VMAR)。VMAR方法可通过以下方法直接访问基本段的对映体纯物质七个步骤,总产率为34%。该合成具有正交保护基策略,这对于即将完成的Lagunamide A合成至关重要。我们还证明,当在各种VMAR中采用立体化学拥挤的α-取代醛时,手性恶唑烷酮的空间体积构成某些挑战。简单合成必需的(2 R,3 S通过Mitsunobu化学方法制备的)-2-羟基-3-甲基戊酸片段也已完成,并掺入了Lagunamide A的C27-C45片段中。