Propargylmagnesium bromide

Propargylmagnesium bromide in diethyl ether diethyl ether... 

To a solution of propargylmagnesium bromide, prepared according to Chapter II,... 

Ph3SnCl and propargylmagnesium bromide give a 90 10 mixture of the acetylenic and allenic tin derivatives, while in the case of Me3SnCl this ratio is 30 70 . 

Apparatus 2-1 flask (Fig. 1) for the addition of bromine and the coupling with propargylmagnesium bromide 6-1 flask (Fig. 4) for the reaction in liquid ammonia. 

The preparation of other 6-aIkylated steroids has also been accomplished with 5,6-epoxides. Thus treatment of 3,3-ethylenedioxy-5a,6a-epoxy steroids (6) with acetylenedimagnesium bromide,propargylmagnesium bromide " or phenylmagnesium bromide, gives the corresponding 6 -ethynyl-, 6j5-propargyl- and 6/ -phenyl-3,3-ethylenedioxy-5a-ols. 

Propargylmagnesium bromide, 84 17 a- (Prop-1 -ynyl) -androst-5-ene-3 /3,17 /3-diol, 74... 

Cadiot et al. reported a synthesis of triphenylallenylplumbane by reaction of propargylmagnesium bromide with triphenyllead chloride. Although the reaction was efficient (70% yield), it suffered from the necessary but tedious preparation of the triphenyllead chloride.158 In contrast, triphenylallenylplumbane can be easily prepared in 75-80% yields by reaction of in situ generated Ph3PbMgBr with propargyl bromide (Equation (129)).159... 

The method used is described by Diysdale, Stevenson, and Sharkey. The methyl ester of butadienoic acid has not been described previously, but the free acid contaminated by 2-bu-tynoic acid has been prepared by Wotiz, Matthews, and Lieb by carbonation of propargylmagnesium bromide. Ethyl butadienoate has been prepared by Eglinton, Jones, Mansfield, and MTiiting by alkali-catalyzed isomerization of ethyl 3-butynoate prepared from 3-butynol by chromic acid oxidation and esterification. 

Propargylmagnesium bromides In preparation of Grignard reagents from pro-pargylic bromides and Mg the use of ZnBr2 as catalyst is preferable to HgCl2 for apparent reasons (toxicity). 

R1 = morpholino R2 = R3 = H) by reacting the imidochloride 66 with propargylmagnesium bromide and, in turn, with PPA failed only the lepidine 67 was obtained.64... 

Ph3SnCl and propargylmagnesium bromide give a 90 10 mixture of the acetylenic... 

Related Reagents. Allenyllithium 1-Methyl-l-(trimethyl-silyl)allene Allyltrimethylsilane Propargylmagnesium Bromide 3-Tiimethylsilyl- 1-propyne. 

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