[reaction: see text]. The IMDA reaction of 9 leads with good stereoselectivity to exo-adduct 10b. The functionalized ABC-ring core in 10 is well suited for the convergent synthesis of analogues of himbacine, a naturally occurring M2 selective muscarine receptor antagonist, as illustrated with the further synthesis of the dehydro-derivative 5.
[反应:请参见文字]。9的I
MDA反应对外加合物10b具有良好的立体选择性。10中的功能化ABC环核心非常适合聚合合成hebacine类似物(一种天然存在的M2选择性毒蕈碱受体拮抗剂),如进一步合成脱氢衍
生物5所示。