one-pot Criegee ozonolysis/acylation protocol to afford acetal-lactone 2. Installation of the allyl side chain on the convex face of the bicyclic system and subsequent reduction provided the desired tetrahydrofuran 4 with the correct relative and absolute stereochemistries. Simple functional group manipulations led to the desired F-ring module 3 of halichondrin B.
                                    C(2)对称的二羟基
环己烯1通过一锅的Criegee
臭氧分解/酰化方案脱对称,得到
缩醛内酯2。烯丙基侧链在双环系统凸面上的安装以及随后的还原反应提供了所需的
四氢呋喃4正确的相对和绝对立体
化学。简单的功能组操作导致了
葫芦素B的所需F环模块3。