Stereochemistry of conjugate addition to 4- and 5-substituted α,β-unsaturated δ-lactones
作者:Ian Fleming、N. Laxma Reddy、Ken Takaki、Anne C. Ware
DOI:10.1039/c39870001472
日期:——
Conjugate addition, especially of the phenyldimethylsilylcuprate reagent, to 4- and 5-substituted α,β-unsaturated δ-lactones [(5) and (18)] is highly selective for the formation of the trans-products [(6), (7), (9), (10), and (19)], the silicon-containing products having 1H n.m.r. coupling constants indicative of distortions from the chair conformation; the silyl group can be converted into a hydroxy
共轭加成,特别是苯基二甲基甲硅烷基铜酸酯试剂向4和5取代的α,β-不饱和δ-内酯[(5)和(18)]的加成对形成反式产物[(6),(图7),(9),(10)和(19)],具有1 H nmr耦合常数的含硅产物表示椅子构象的变形;甲硅烷基可以转化为羟基以得到内酯(8)和(20)。