Tertiary Amine Mediated Tandem Cross-Rauhut-Currier/Acetalization Reactions: Access to Functionalized Spiro-3,4-Dihydropyrans
作者:Weijun Yao、Yihua Wu、Gang Wang、Yiping Zhang、Cheng Ma
DOI:10.1002/anie.200905091
日期:2009.12.14
γ‐Proton transfer furnished the highly selective title reaction in which cyclic β‐haloenals 1 react with β,γ‐unsaturated α‐ketoesters 2 to generate functionalized spiro‐3,4‐dihydro‐2H‐pyrans 3 having an α‐quaternary carbon center and an adjacent vinyl halide group in skeleton. DBU=1,8‐diazabicyclo[5.4.0]undec‐7‐ene, Tos=4‐toluenesulfonyl.
γ-质子传递布置,其中环状β-haloenals高度选择性标题反应1与β,γ不饱和α酮酯反应2来生成官能螺-3,4-二氢-2 ħ -pyrans 3具有α-季碳中心和骨架中相邻的乙烯基卤化物基团。DBU = 1,8-二氮杂双环[5.4.0]十一月-7-烯,Tos = 4-甲苯磺酰基。