Asymmetric Synthesis of Dihydroindanes by Convergent Alkoxide-Directed Metallacycle-Mediated Bond Formation
作者:Stephen N. Greszler、Holly A. Reichard、Glenn C. Micalizio
DOI:10.1021/ja2105043
日期:2012.2.8
A convergent synthesis of highlysubstituted and stereodefined dihydroindanes is described from alkoxide-directed Ti-mediated cross-coupling of internal alkynes with substituted 4-hydroxy-1,6-enynes (substrates that derive from 2-directional functionalization of readily available epoxy alcohol derivatives). In addition to describing a new and highly stereoselective approach to bimolecular [2 + 2 +
Stereoselectivity and Regioselectivity in the Segment-Coupling Prins Cyclization
作者:James J. Jaber、Kazuhiko Mitsui、Scott D. Rychnovsky
DOI:10.1021/jo010232w
日期:2001.6.1
allylic alcohols leads to fragmentation rather than a disfavored 5-endo-trig cyclization. Dienols in which one alkene is allylic and the other alkene is homoallylic cyclizeefficiently and produce the tetrahydropyrans 49-54, Table 3. Dienols with two homoallylic alkenes cyclize with modest to high regioselectively, generating tetrahydropyrans 40-45, Table 2. The relative rates for cyclization decrease