Nazarov Reactions Intercepted by (4 + 3) Cycloadditions with Oxygen-Substituted Dienes
作者:François M. LeFort、Vinayak Mishra、Graham D. Dexter、Timothy D. R. Morgan、D. Jean Burnell
DOI:10.1021/acs.joc.5b00914
日期:2015.6.5
The oxyallyl cation intermediate from the Lewisacidmediated Nazarov reaction of an allenyl vinyl ketone was intercepted by acyclic, 2-silyloxy-substituted butadienes by highly regioselective (4 + 3) cycloadditions. Stereoselectivity was often modest, but in some instances steric interactions were responsible for high selectivity. The results are consistent with concerted (4 + 3) cycloadditions. In
A Convergent Total Synthesis of the Telomerase Inhibitor (±)-γ-Rubromycin
作者:Michael Wilsdorf、Hans-Ulrich Reissig
DOI:10.1002/anie.201400315
日期:2014.4.22
The totalsynthesis of the human telomeraseinhibitor γ‐rubromycin in its racemic form was accomplished in 3.8 % overall yield. The key feature of this synthesis is an efficient acid‐catalyzed spiroketalization for the construction of the spiroketal core. The required electronically well‐balanced spiroketal precursor was obtained by the convergent assembly of a naphthyl‐substituted aldehyde, an α‐