(bis-THF) fragment of the proposed structure of iriomoteolide-2a has been synthesized via stepwise double intramolecular SN2-type etherifications. The C11 and C16 stereogenic centers could be secured in the forms of propargyl alcohols by asymmetric transfer hydrogenation of the corresponding propargyl ketones. The C9–C12 THF ring was first constructed via a tandem asymmetric dihydroxylation (AD)–SN2 sequence
通过逐步双分子内S N 2型醚化合成了拟合成的iriomoteolide-2a结构的C6-C18双-
四氢呋喃(bis-THF)片段。C11和C16立体异构中心可以通过相应炔丙基酮的不对称转移氢化来以炔丙基醇的形式固定。的C9-C12环THF首先通过串联不对称二羟基化(AD)-S构造Ñ 2序列而C13-C16环THF经由分子内晚节安装Ñ手性
甲磺酸炔
丙酯的2个反应。在后面的THF环形成过程中,未观察到在炔丙基碳上的差向异构。自最初提出(9 R,11 S,12 R)iriomoteolide-2a的构型最近已修订为(9 S,11 R,12 S),通过使用手性
配体的相反对映体对AD和C不对称转移氢化。