A Homologation of Aldehydes and Ketonesviathe Formation and the Subsequent Pummerer-type Ring Fission of 2-Methylsulfinyl-5,6-dihydro-4H-1,3,4-thiadiazine Derivatives
A Homologation of Aldehydes and Ketones<i>via</i>the Formation and the Subsequent Pummerer-type Ring Fission of 2-Methylsulfinyl-5,6-dihydro-<i>4H</i>-1,3,4-thiadiazine Derivatives
A two-carbon homologation of aldehydes and ketones was achieved by using a sequence involving the formation and the subsequent Pummerer-type ring fission of 5,6-dihydro-4H-1,3,4-thiadiazine rings possessing methylsulfinyl functionality at C-2.
followed by mCPBA oxidation. The subsequent Pummerer-type ring fission of the rings was performed by treating with trifluoroacetic anhydride or trifluoromethanesulfonic anhydride at −78 °C to give α,β-unsaturated esters and ketones in modest yields. Thus, this reaction sequence was regarded as being a new method for the two-carbon homologation of aldehydes and ketones.