tricylic intermediate 3a, for the total synthesis of the C20-nor analogue of salvinorin A, was prepared in seven steps from 3-furaldehyde. Key steps involved a highly regio- and diastereoselective Lewis acid assisted Diels−Alder reaction followed by base-promoted epimerization and a completely stereoselective conjugate reduction.
用于全合成Salvinorin A的C 20 -nor类似物的关键三聚中间体3a是由3-
呋喃甲醛分七个步骤制备的。关键步骤涉及高度区域和非对映选择性的
路易斯酸辅助的Diels-Alder反应,然后是碱促进的差向异构化和完全立体选择性的共轭物还原。