Vinyl magnesium chloride

A three-step synthesis starts from cyclododecanone. Reaction with chlorine gives 2-chlorocyclododecanone which is reacted with 2 mol of vinyl magnesium chloride to give 1,2-divinylcyclododecan-l-ol. This is finally converted into 5-cyclohexadecen-l-one by an oxy-Cope rearrangement [126] ... 

L-Homoserinal 38 (800 mg, 2.09 mmol), prepared from L-aspartic acid in a nine-step sequence, was dissolved in 20 mL of dry EtjO. The solution was cooled under argon to —78°C, and vinyl magnesium chloride in tetrahydrofuran (THF 15%, 1.5 mL, 2.5 mmol) was added dropwise. The reaction mixture was stirred at the same temperature for 1 h. Water (125 mL) was then added, and the organic phase was separated. The aqueous solution was extracted with Et20 (2 x 50 mL), and combined organic layers were washed with water (2 x 30 mL), brine (30 mL), and dried (MgS04). Evaporation of solvents and flash... 

In a similar fashion, chromium tricarbonyl complexes of aryl ketones are exclusively alkylated and reduced from the exo face relative to the metal. For example, addition of vinyl magnesium chloride to the substituted tetralone complex (42) affords the alcohol (43) exclusively with an antirelationship between the incoming nucleophile and the chromium tricarbonyl group (Scheme 83). This was used in a synthesis of 11-epi-helioporin B. 2-Trimethylsilyl-substituted benzaldehyde complexes undergo an interesting... 

Alkeneboronic esters and acids are also readily available, as in the addition of vinyl-magnesium chloride" to trimethyl borate below —50°C, followed by hydrolysis." ... 

C13H20O, Mr 192.30, < ,q 1.008-1.016, ng5 1.444-1.448, not found to occur in nature, is a colorless to pale yellow liquid with green, fruity, floral odor reminiscent of galbanum. One of several cited syntheses involves as a key step a double vinyl magnesium chloride addition to methyl 3,3-dimethyl-6-cyclohexene-l-carboxylate to give the title compound [128]. 

For the synthesis of the naturally occurring (6 R)-p,e-carotene (7), (RJ-a-ionone ((R)-79) was reacted with vinyl magnesium chloride (140) to give the Ci5-alcohol 158 which was... 

Alkyl- or aryl-cycloheptatrienes are formed readily by the reaction of tropylium salts with Grignard regents or with organo-lithium derivatives [3,16,19,83]. For example by using vinyl magnesium chloride, vinylcycloheptatriene and hence vinyltropylium salts have been prepared [32]. With lithium cyclopentadienide cyclopenta-dienylcycloheptatriene is formed and not an ionic tropylium cyclopentadienide [19,35] ... 

Bates and his team also reported a variant of the above route with vinyl-magnesium chloride replacing the alkynyUithium in the initial addition step... 

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