Abnormal Nucleophilic Substitution on Methoxytropone Derivatives: Steric Strategy to Synthesize 5‐Substituted Azulenes
作者:Neha Rani Kumar、Abhijeet R. Agrawal、Sanjio S. Zade
DOI:10.1002/chem.201902702
日期:2019.11.7
optoelectronic materials. Despite the routes available for the preparation of substituted azulene derivatives, there remain few methods that allow regioselective substitution on the seven-membered ring of azulenes due to the subtle reactivity difference among the various positions. This report explores the reactivity of substituted tropolones as the azulene precursors and also provides a new method to create
A Diastereoselective Silver(I) Promoted gem-Dibromocyclopropane Ring Opening Reaction via an Anchimeric Assisted Transannular Benzoate Migration
作者:George A. O'Doherty、Matt S. Mortensen、Aaron C. Schmitt、Catherine M. Smith、Eric A. Voight
DOI:10.3987/com-05-s(t)69
日期:——
prepared in only six steps from benzene or four steps from 7,7-dibromo-3-norcarene. The key to this approach was the discovery of a stereoselective transannular benzoate migration, which occurred via tandem anchimeric assistance in a silver(I) promoted gem-dibromocyclopropane ring opening reaction.
A novel synthesis of nezukone via the rearrangement of a bicyclic isomer: evidence for the intermediacy of heptafulvenes
作者:Martin G. Banwell、G. Lance Gravatt、Cliff E. F. Rickard
DOI:10.1039/c39850000514
日期:——
The bicyclic methylenecyclopropane (2) is converted into nezukone (1) in 61% yield; evidence is presented which suggested heptafulvenes are involved in this conversion.
A Convenient Preparation of 7,7-Dimethyl-1,3,5-cycloheptatriene
作者:James H. Rigby、Anne-Roberte Bellemin
DOI:10.1055/s-1989-27190
日期:——
Described is a four-step synthesis of 7,7-dimethyl-1,3,5-cycloheptatriene which starts from readily available 1,4-cyclohexadiene. Monocyclopropanation of this compound with dibromocarbene followed by replacement of the halogens with methyl groups using a higher order cuprate reagent provides the corresponding norcarene which is subjected to a bromination-dehydrobromination sequence to give the title compound.