A new strategy to access highly enantioenrichedcycliccompounds (up to 98%) is proposed using ω-ethylenic allylic substrates through a one-pot asymmetricallylicalkylation and ring-closingmetathesis. Such starting compounds can be seen as synthetic equivalents of cyclicallylic substrates.
The present invention relates to a process for producing an alkenyl mercaptan (2), comprising reacting an alkenyl halide (1) with an alkali hydrosulfide, wherein the reaction is carried out in the presence of a disulfide (3) in an amount of 0.5 part by weight or more based on 100 parts by weight of the total amount of the alkenyl halide (1) and the alkenyl mercaptan (2).
Verfahren zur Herstellung von halogenalkylsubstituierten Oxiranen
申请人:BAYER AG
公开号:EP0000554A1
公开(公告)日:1979-02-07
Die vorliegende Erfindung betrifft ein verbessertes Verfahren zur Herstellung von halogenalkylsubstituierten Oxiranen aus halogenalkylsubstituierten Olefinen und Percarbonsäuren in organischer Lösung in hohen Ausbeuten und großer Reinheit welches dadurch gekennzeichnet ist, daß man ein chloralkyloder bromalkylsubstituiertes Monoolefin der allgemeinen Formel
mit einer Lösung einer 3 bis 4 Kohlenstoffatome enthaltenden Percarbonsäure in einem chlorierten, 1 bis 8 Kohlenstoffatome enthaltenden Kohlenwasserstoff bei einem Molverhältnis von Monoolefin zu Percarbonsäure von 1,1 : 1 bis 10 : 1 und bei einer Temperatur von 30 bis 100°C umsetzt.
An improved process for producing allyl bromides by halogen exchange by reaction of an allyl chloride, with a metal bromide, wherein the reaction is conducted in an aprotic polar solvent. The allyl bromides obtained by the process of the invention are useful as intermediates for producing medicines, agricultural chemicals, dyes, and the like.
Methods of making telechelic oligomers, methods of making block copolymers, and novel block copolymers
申请人:——
公开号:US20020115793A1
公开(公告)日:2002-08-22
A method of making telechelic oligomers comprises reacting a substrate compound selected from the group consisting of relatively high molecular weight polymers with a chain transfer agent in the presence of an alkali metal catalyst. The telechelic oligomers thus produced may then be reacted with monomers according to known polymerization techniques in order to produce block copolymers.