A Convenient and Useful Method of Preparation of<i>α</i>-Bromo Enones from the Corresponding Enones Using Organic Ammonium Tribromide (OATB)
作者:Gopal Bose、Pankaj M. Bujar Barua、Mihir K. Chaudhuri、Dipak Kalita、Abu T. Khan
DOI:10.1246/cl.2001.290
日期:2001.4
Various acyclic α-bromo enones 2 as well as cyclic α-bromo enones 4 can be prepared from the corresponding acyclic enones 1 and cyclic enones 3 respectively, in a one-pot procedure by employing organic ammonium tribromide, such as cetyltrimethylammonium tribromide (CetTMATB) or tetrabutylammonium tribromide (TBATB) in presence of K2CO3 in dichloromethane at 0 °C to room temperature under very mild
A Novel and One Step Procedure for Preparation of α-Bromo-α,β-unsaturated Carbonyl Compounds
作者:K. G. Akamanchi、G. V. Ramanarayanan、Vidyanand G. Shukla
DOI:10.1055/s-2002-35600
日期:——
A new one step method is developed for the preparation of a-bromo-α,β-unsaturated carbonylcompounds in moderate to good yields from corresponding α,β-unsaturated carbonylcompounds using DMP [1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one] and tetraethylammonium bromide under neutral and mild reaction conditions at room temperature.
1,2,3,4‐Tetrahydro‐4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohexanone with 2‐methylbenzenethiol and annulating the product with the aid of polyphosphoric acid. A mixture of 1,2,3,4‐tetrahydro‐4,6‐dimethyldibenzothiophene and 4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohex‐2‐en‐1‐one with 2‐methylbenzenethiol and annulating the product
Five- and six–membered cyclic α-acylvinyl anionic synthons: synthesis of α-trimethylsilyl-α,β-unsaturated cycloalkenones and their conversion into 2-(hydroxydimethylsilyl)cycloalk-2-enones through carbon–silicon bond scission
作者:Divya Jyothi、HariPrasad Suresh
DOI:10.3998/ark.5550190.0013.618
日期:——
Five- and six-membered I±-trimethylsilyl-I±,I²-unsaturated cycloalkenones were prepared by the Wurtz-Fittig coupling reaction of the corresponding 6-bromo-1,4-dioxaspiro4,ncycloalk-6-enes with sodium and chlorotrimethylsilane. Upon treatment with anhydrous AlCl3, the compounds underwent carbon-siliconbondscission to yield a novel class of compounds: the 2-(hydroxydimethylsilyl)cycloalk-2-enones.