Stereochemical Diversity through Cyclodimerization: Synthesis of Polyketide-like Macrodiolides

An expeditious procedure for the direct formation of stereochemically well-defined macrodiolides is described. Cyclodimerizations of enantioenriched C7 and C8 hydroxy esters 6 in the presence of catalytic amounts of distannoxane transesterification catalysts afford 14- to 22-membered macrodiolides 7−9 bearing up to six stereocenters. Additional structural diversity is introduced by further stereoselective reactions on selected macrodiolides 7a, 7g, 10a, and 11.本研究报道了一种可直接构建立体化学构型明确的大环二醇酯（macrodiolides）的简便高效方法。在催化量二锡氧烷类酯交换催化剂作用下，对映体富集的C7及C8羟基酯6发生环二聚反应，生成含多达6个立体中心的14至22元大环二醇酯7~9。通过对选定的大环二醇酯7a、7g、10a及11进行后续立体选择性反应，可进一步引入结构多样性。