[reaction: see text]. A novel convergent approach to fully functionalized ring C allocolchicinoids is developed which is based on the benzannulation reaction of Fischer carbene complexes with alkynes. The efficacy of this strategy was established with the conversion of bromide 1a (R1 = Me, R2 = H) to the biaryl phenol 3a (R = Me, R(L) = Pr, R(S) = H) via the carbene complex 2a. Bromide 1b (R1 = t-Bu
[反应:请参见文字]。基于Fischer卡宾配合物与
炔烃的苯并环反应,开发了一种新的收敛方法,用于完全官能化的环C allocolchicinoids。通过卡宾配合物将
溴化物1a(R1 = Me,R2 = H)转化为联芳基
苯酚3a(R = Me,R(L)= Pr,R(S)= H)确立了该策略的有效性2a。然后将
溴化物1b(R1 = t-Bu,R2 = OMe)用于非对映体二十碳五烯类
固醇3b(R = Me,R(L)= Pr,R(S)= H)的类似制备。