Selective Cross-Acyloin Condensation Catalyzed by Thiazolium Salt. Formation of 1-Hydroxy 2-Ones from Formaldehyde and Other Aldehydes

Article abstract of DOI:10.1021/jo00205a010

The condensation of formaldehyde with another aldehyde catalyzed by 3-ethylbenzothiazolium bromide in the presence of triethylamine gives selectively 1-hydroxy 2-ones.This selective cross-acyloin condensation indicates an inverse selectivity in the reactions of the conjugate base of thiazolium salt 17 and of the carbanion bound to thiazolium ring 19 toward aldehyde.