2-Acetyl-1-pyrroline (2AP) is an organic compound with the formula CH3C(O)C4H6N. In terms of structure, it is a derivative of 1-pyrroline. It is an aroma compound and flavor that gives freshly baked bread, jasmine rice and basmati rice, the herb pandan, and bread flowers their customary smell. Many observers describe the smell as similar to "hot, buttered popcorn" 2AP and its structural homolog, 6-acetyl-2,3,4,5-tetrahydropyridine of similar smell, can be formed by Maillard reactions during heating of food such as the baking of bread dough. Both compounds have odor thresholds below 0.06 ng/L.