A series of polysubstituted tetrahydropyrimidines were synthesized in moderate to good yields via a one-pot, four-component reaction of an alkyne, formaldehyde, and amines in solid media acidic Al2O3. The advantages of this protocol include mild reaction conditions, broad substrate scope, and environmentally friendly reaction media.
An efficient synthesis of tetrahydrofuro[3,2-b]quinolin-2（3H）-ones from α-angelica lactone and 2-aminobenzaldehydes via a tandem Aldol-Michael addition is described. The reactions were carried out using DBU as the base in i-Pr OH at 0 ℃, affording tetrahydrofuro[3,2-b]quinolin-2（3H）-ones in moderate to good yields.
