The one-pot reaction of valerolactone with nitriles in the presence of triflic anhydride affords 2,4-disubstituted pyrano[2,3-d]pyrimidines. Subsequent addition of methyl thiocyanate leads to 2,4-bis(methylthio)pyranopyrimidines which can easily be converted into the corresponding methylsulfonyl derivatives. The reaction of these derivatives with different nucleophiles produces a variety of substituted pyranopyrimidines.
The one-pot reaction of valerolactone with nitriles in the presence of triflic anhydride affords 2,4-disubstituted pyrano[2,3-d]pyrimidines. Subsequent addition of methyl thiocyanate leads to 2,4-bis(methylthio)pyranopyrimidines which can easily be converted into the corresponding methylsulfonyl derivatives. The reaction of these derivatives with different nucleophiles produces a variety of substituted pyranopyrimidines.