2-Cycloalkenones Grignard additions

TABLE 3. Cu/NHC-catalyzed addition of Grignard reagents to 3-substituted-2-cycloalkenones... 

Alkynyltrialkylborates are versatile intermediates to 1,4-dikelones and y-oxo-esters, -nitriles, and -alkynes, as well as substituted ketones. A route from a -unsaturated cycloalkenones to 1,4-diketones is available wherein an aldehyde undergoes photoaddition to the alkene unit, and a variety of 1,4-diones is obtained by thiazolium salt-catalysed addition of aldehydes to but-2-enone. Monoacetalized 1,4-diketones and y-keto-aldehydes are formed on reaction of acyl chlorides with the Grignard reagents (13) and (14), respectively. 

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