摘要
以4-甲氧基-2-溴代丁烯内酯为合成子,在温和条件下与不同的亲核试剂通过串联的双Michael加成及分子内的亲核取代反应,得到螺环-环丙烷类化合物8a～8d.通过元素分析,IR,1HNMR,13CNMR和MS对化合物进行了结构表征,其中化合物8d经单晶X射线衍射测定,确定了其立体化学结构.
Cyclopropane-containing natural products have received considerable attention as the synthetic targets due to their significant effects on bioactivities with concomitant medical and agricultural implications. We recently reported a valuable synthetic route to spiro-cyclopropane-butinolied derivatives containing multiple stereogenic centers, using 5-L-menthyloxy-3-bromo-2(5H)-furanone, and different nucleophiles by tandem double Michael addition/internal nucleophilic substitution. On the basis of the previous work, the synthesis of 4-methoxy-2-bromobutyrolactone (4) was conveniently achieved from 4-hydroxybutyrolactone (2) as a starting material through the acetalization of methanol. 2-Bromobutyrolactone (4) as a synthon reacts with various nucleophiles under mild conditions to form the diversely functionalized spiro-cyclopropane derivatives 8a—8d via tandem double Michael addition/intramolecular nucleophilic substitution. Spiro-cyclopropane compounds 8a—8d were identified on the basis of their elemental analysis and spectroscopic data, such as IR, ()~1H NMR, ()^(13)C NMR and MS. The stereochemistry and configuration of the spiro-cyclopropane compound 8d was measured by X-ray crystallography. This result provides an efficient synthetic route to the interesting functionalized target molecules 8 with 4-methoxy-2-bromobutyrolactone (4) as a cheap substrate. It could be furnished further an important synthetic strategy for some complex cyclic natural and nonnatural products.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第5期860-864,F006,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:29672004)资助.
