A New Entry to 5-Unsubstituted 3-Acyltetramic Acids from Aldehydes
Reaction of aldehydes (prim-, sec-, and tert-) with diazoacetamide (8,9) of N-substituted glycinate in the presence of Zr(IV) chloride in CH2Cl2 affords β-keto amides (11,12) in good to high yields, which on treatment with n-Bu4NF in THF are led to N-prot