Alpha-hydroxyketones

In 1921, Neuberg and Hirsch discovered that yeasts could condense added ben-zaldehyde with pyruvate-derived acetaldehyde to form the chiral product, l-(-f) phenylacetylcarbinol (also named Neuberg s ketone). This alpha-hydroxyketone (acyloin) can easily be chemically converted into L-(-)-ephedrine, an important broncho dilator still made by a bioprocess. 

A blend of 2,4,6-Trimethylbenzoyldiphenylphosphine oxide, alpha-hydroxyketone and benzophenone derivative. It is a liquid photoinitiator which can be easily incorporated by simply stirring into your resin system. 

Details are given of the development of a technique for the direct evaluation of volatile organic compounds during the radiation curing process. This method was used to evaluate the release of benzaldehyde from commercially available alpha-hydroxyketones during curing. 8 refs. 

Oxabicyclic ketones have also been further derivatized to the alpha-oxidation products which are in turn cleaved, offering still another option for carbon-carbon bond scission. For example, hydroxyketone 114, available in > 98 % ee from the parent ketone, was cleaved by lead tetraacetate to afford an excellent yield of the hydroxyester 115, a key intermediate in Noyori s synthesis of showdomycin, Eq. 86 [121,129]. In this case, the ozonolysis of the silyl enol ether of the parent ketone led to complex mixtures, demonstrating the complementarity of these approaches. 

Platonova and coworkers " synthesized materials by the reaction of zirconocene dichloride with aromatic polymers bearing alpha-diketones and alpha-hydroxyl ketone moieties. The product was formed through reaction with the hydroxyketone functional group. 

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