Fused‐ring nitrogen and sulfur heterocycles by a tandem S
<sub>N</sub>
2‐michael addition reaction
作者:Richard A. Bunce、Sharadsrikar V. Kotturi、Christopher J. Peeples、Elizabeth M. Holt
DOI:10.1002/jhet.5570390531
日期:2002.9
A tandem SN2-Michael addition reaction has been developed for the synthesis of cis- and trans-fused nitrogen and sulfur heterocycles from the cis and trans isomers of ethyl (±)-(2E)-3-[2-(iodomethyl)cyclo-hexyl]-2-propenoate. Octahydro-1H-isoindole-1-acetic acid and octahydrobenzo[c]thiophene-1-acetic acid derivatives have been prepared and their stereochemistries elucidated using NMR and X-ray crystallo-graphic
已开发了串联的S N 2-Michael加成反应,用于由乙基(±)-(2 E)-3- [2-(碘甲基)的顺式和反式异构体合成顺式和反式稠合的氮和硫杂环)环己基] -2-丙烯酸酯。制备了八氢-1 H-异吲哚-1-乙酸和八氢苯并[ c ]噻吩-1-乙酸衍生物,并使用NMR和X射线晶体成像方法阐明了它们的立体化学。顺式和反式的环化底物稠合的环可容易地以四个步骤从已知化合物获得。从80-85%和立体化学SELEC-tivities相对于侧链环化产率范围从12.5-16变化:1的顺式-融合结构以6-7.5:1的反式-融合结构。提出了用于闭环的过渡态中的立体相互作用以合理化所观察到的偏好。