New synthetic applications of organotin compounds: synthesis of stereodefined 2-iodo-2-alkenones, 2-substituted (E)-2-alkenones and 2-methyl-2-cycloalkenones
作者:Fabio Bellina、Adriano Carpita、Donatella Ciucci、Massimo De Santis、Renzo Rossi
DOI:10.1016/s0040-4020(01)81297-7
日期:1993.5
product, (E)-13f with the compound derived from methyl transfer, (E)-13e. The couplings involving (Z)-8a, (Z)-8b, (Z)-8c and (Z)-8d proceeded with clean retention of stereochemistry, but the Pd-catalyzed reaction between (E)-8c and SnMe4 afforded a stereoisomeric mixture of 13e. On the contrary, the coupling between (E)/(Z)-8b and SnMe4 produced stereoisomerically pure (E)-13c. Two 2-iodo-2-cycloalkenones
3-碘-3-壬烯-2-酮,8a,2-碘-1-苯基-2-辛烯-1-酮,8b,2-碘-1,3-二苯基-2-丙烯-1的立体异构混合物-one 1c(8c)和(Z)-3-io-4--4-苯基-3-buten-2-one(8d)已通过包含相应Pd催化的相应1-炔基之间反应的反应序列有效合成酮10和Bu 3 SnH,然后进行碘去甲磺酰化。在日光下并使用催化量的I 2进行的立体变异实验表明,Z立体异构体8a,8b和8c可以通过MPLC在硅胶上与相应的E立体异构体分离,以及化合物(Z)-8d比其E立体异构体更稳定。化合物8A-d进行使用C Pd-催化的交叉偶联反应6 ħ 5 SnMe 3,CH 2 CH-SnBu 3和SnMe 4提供有效的路线相应的2-取代的2-烯酮,13。然而,(之间的Pd催化的反应Ž) -图8c和PhSnMe 3得所期交叉耦合产物的混合物(ë) - 13F与甲基转移衍生的化合物,(ë)