Pinacols synthesis

HOLLEMANN Pinacol Synthesis Oimenzalion of ketones to 1.2-diols by means of Mg and other metals... 

Diols (pinacols) can be synthesized by reduction of aldehydes and ketones with active metals such as sodium, magnesium, or aluminum. Aromatic ketones give better yields than aliphatic ones. The use of a Mg—Mgl2 mixture has been called the Gomberg-Bachmann pinacol synthesis. As with a number of other reactions involving sodium, there is a direct electron transfer here, converting the ketone or aldehyde to a ketyl, which dimerizes. 

B. P. Mundy, D. R. Bruss, Y. Kim, R. D. Larsen, R. J. Wamet, Tetrahedron Letters 1985,26, 3927 Gomberg-Bachmann Pinacol Synthesis... 

Burke, B. J., Lebsack, A. D., Overman, L. E. Scope and limitations of the thionium ion-initiated prins-pinacol synthesis of carbocycles. Synlett 2004, 1387-1393. 

This reaction is called the pinacol synthesis, and is of general applicability. It works best for symmetrical aromatic ketones, because of the high stability of the aromatic ketyl intermediate, which incidentally is blue in colour. 

Other references related to the Gomberg-Bachmann pinacol synthesis are cited in the literature." ... 

Gomberg-Bachmann pinacol synthesis 1, 689 Gomberg reaction, improved 16, 842... 

Cohen, F., MacMillan, D. W. C., Overman, L. E., Romero, A. (2001). Stereoselection in the Prins-pinacol Synthesis of Acyltetrahydrofurans, Organic Letters, 3,1225-1228. 

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