Butenolide
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Furan-2-one.svg/220px-Furan-2-one.svg.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/c4/3-methyl-2H-furo-2%2C3-c-pyran-2-one.png/220px-3-methyl-2H-furo-2%2C3-c-pyran-2-one.png)
Butenolides are a class of lactones with a four-carbon heterocyclic ring structure.[2] They are sometimes considered oxidized derivatives of furan. The simplest butenolide is 2-furanone, which is a common component of larger natural products and is sometimes referred to as simply "butenolide". A common biochemically important butenolide is ascorbic acid (vitamin C). Butenolide derivatives known as karrikins are produced by some plants on exposure to high temperatures due to brush fires. In particular, 3-methyl-2H-furo[2,3-c]pyran-2-one was found to trigger seed germination in plants whose reproduction is fire-dependent.[1]