New synthesis of thiiranes by fluoride ion-promoted reaction of S-methyl-S′-trimethylsilylmethyl N-(p-toluenesulfonyl)dithioiminocarbonate and 2-(trimethylsilylmethylthio)thiazoline with aldehydes
introduction of a thioformaldehyde unit to a carbonyl carbon. The reaction of these compounds with aldehydes in the presence of cesium fluoride afforded thiiranes via the 1,3-dipolarcycloaddition of iminothiocarbonyl ylide to CO double bond.