2-Acetyl-1-pyrroline

2-Acetyl-1-pyrroline (2AP) is an aroma compound and flavor that gives freshly baked bread, jasmine rice and basmati rice, the herb pandan (Pandanus amaryllifolius), and bread flowers (Vallaris glabra) their customary smell.^[1] Many observers describe the smell as similar to "hot, buttered popcorn", and it is credited for lending this odor to the scent of binturong (bearcat) urine.^[2] Fresh marking fluid (MF) and urine of the tiger (Indian, Amur or Siberian) and Indian leopard also have a strong aroma due to 2AP.^[3]

2-Acetyl-1-pyrroline

Skeletal formula of 2-acetyl-1-pyrroline
Names
Preferred IUPAC name 1-(3,4-Dihydro-2H-pyrrol-5-yl)ethan-1-one
Other names 1-(3,4-Dihydro-2H-pyrrol-5-yl)ethanone 2-Acetyl-1-pyrroline
Identifiers
CAS Number	85213-22-5 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:67125 N
ChemSpider	456071 Y
MeSH	2-Acetyl-1-pyrroline
PubChem CID	522834
UNII	IGC0W6LY94 Y
CompTox Dashboard (EPA)	DTXSID40335080
InChI InChI=1S/C6H9NO/c1-5(8)6-3-2-4-7-6/h2-4H2,1H3 Y Key: DQBQWWSFRPLIAX-UHFFFAOYSA-N Y InChI=1/C6H9NO/c1-5(8)6-3-2-4-7-6/h2-4H2,1H3 Key: DQBQWWSFRPLIAX-UHFFFAOYAG
SMILES CC(=O)C1=NCCC1
Properties
Chemical formula	C6H9NO
Molar mass	111.144 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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.^[4]

Structure and properties

2AP is a substituted pyrroline and a cyclic imine as well as a ketone.