Stereoselective Synthesis of (E)- and (Z)-Acetals of Pent-2-en-4-yn-1-al and Related Dienynes and Dienediynes
作者:Franck Suzenet、Jean-Luc Parrain、Jean-Paul Quintard
DOI:10.1002/(sici)1099-0690(199911)1999:11<2957::aid-ejoc2957>3.0.co;2-7
日期:1999.11
(3E)-5,5-Diethoxypent-3-en-1-yne was stereospecifically prepared by Sonogashira–Linstrumelle cross-coupling between (E)-3-iodoacrolein diethylacetal and (trimethylsilyl)acetylene. The (Z) isomer was obtained by Stille cross-coupling between the corresponding (Z)-vinyltin and 1-bromo-2-(trimethylsilyl)acetylene. In the case of the (E) isomer, transacetalisation occurred without isomerization affording
(3 E)-5,5-Diethoxypent-3-en-1-yne是通过(E)-3-碘丙烯醛二乙缩醛与(三甲基甲硅烷基)乙炔之间的Sonogashira–Linstrumelle交叉偶联立体定向制备的。(Z)异构体通过在相应的(Z)-乙烯基锡和1-溴-2-(三甲基甲硅烷基)乙炔之间的Stille交叉偶联而获得。在(E)异构体的情况下,发生转缩醛化而不进行异构化,从而提供了多种被保护为缩醛的(E)-烯醛。在适当的实验条件下,通过sp–sp均相耦合也可能获得相应的(E,E)-二烯二炔。