Addition of Grignard reagents to O-trimethylsulylated cyanohydrins: Synthesis of acyloins

✍ Scribed by Larry R. Krepski; Steven M. Heilmann; Jerald K. Rasmussen

• Book ID: 104221586
• Publisher: Elsevier Science
• Year: 1983
• Tongue: French
• Weight: 242 KB
• Volume: 24
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)88265-9

✦ Synopsis

Grignard reagents have been found to react readily with Otrimethylsilylated cyanohydrins to afford , after acid hydrolysis of intermediates, good yields of acyloins. The utility of a-hydroxyketones (acyloins) in organic chemistry is attested to by the great variety of methods which have been developed for their preparation.' Although the sodium/chlorotrimethylsilane induced "acyloin condensation"2 of esters and the cyanide catalyzed "benzoin condensation"3 of aromatic aldehydes are useful for the respective syntheses of symmetrical acyloins and benzoins, the preparation of unsymmetrical a-hydroxyketones is usually more difficult. Of the many pertinent synthetic methods, few have the dual advantages of simplicity and generality. One established3'4 method for the preparation of acyloins involves the addition of a Grignard reagent to a cyanohydrin (eq.