Gamma-Butyrolactone

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Gamma-Butyrolactone

General
Systematic name	Dihydrofuran-2(3H)-one
Other names	GBL, butyrolactone, 1,4-lactone, 4-butyrolactone, 4-hydroxybutyric acid lactone, and gamma-hydroxybutyric acid lactone
Molecular formula	C₄H₆O₂
SMILES	O=C1CCCO1
Molar mass	86.089 g/mol
Appearance	Colorless liquid
CAS number	[96-48-]
Properties
Density and phase	1.144 g/mL
Solubility in water	Hygroscopic
Melting point	-45 °C
Boiling point	204 - 205 °C
Acidity (pK_a)	?
Viscosity	? cP at ?°C
Structure
Dipole moment	? D
Hazards
MSDS	External MSDS
Main hazards	Harmful
NFPA 704
Flash point	98 °C (closed cup)
R/S statement	R: R22 R36 S: S26 S36
RTECS number	?
Related compounds
Related compounds	?
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

gamma-Butyrolactone, also known as GBL, butyrolactone, 1,4-lactone, 4-butyrolactone, 4-hydroxybutyric acid lactone, and gamma-hydroxybutyric acid lactone, is a hygroscopic colorless oily liquid with a weak characteristic odor and moderate solubility in water (≥ 10 g / 100 ml). gamma-Butyrolactone is a common solvent and reagent in chemistry and is used as an aroma compound, as a stain remover, as a paint stripper, and as a gamma-hydroxybutyric acid (GHB) precursor and substitute.

1 Chemistry
- 1.1 A Natural Component In Wine
2 Recreational use
- 2.1 Restricting the use of GBL
3 Notes
4 See also
5 External links

[edit] Chemistry

gamma-Butyrolactone is a lactone. It is hydrolyzed under basic conditions, for example in a sodium hydroxide solution into sodium gamma-hydroxybutyrate, the sodium salt of gamma-hydroxybutyric acid. Under acidic conditions it forms an equilibrium mixture of both compounds. gamma-Butyrolactone can be synthesized from gamma-hydroxybutyric acid by removal of water or by distillation from such a mixture. It may also be obtained via oxidation of tetrahydrofuran (THF). One such process, which affords GBL in yields of up to 80%, utilises bromine generated in situ from an aqueous solution of sodium bromate and potassium hydrogen sulfate ^[1].

[edit] A Natural Component In Wine

The compound gamma-butyrolactone (GBL) was found in extracts from samples of unadulterated wines. This finding indicates that GBL is a naturally occurring component in some wines and may be present in similar products. The concentration detected was approximately 5 microg/mL and was easily observed using a simple extraction technique followed by GC/MS analysis. These results illustrate the need to carefully examine an allegedly adulterated sample's matrix before determining a sample was laced with GBL.

[edit] Recreational use

GBL is a prodrug of GHB. Metabolism takes place in stomach and blood plasma. GBL is longer acting and has a shorter onset than GHB. Otherwise, effects are similar to GHB, although weight for weight it is significantly more powerful, meaning dosage must be lowered accordingly. If ingested undiluted through the oral route, GBL can irritate innards. It is possible for oral ingestion of GBL to cause nausea and other similar problems, possibly more so than with GHB.

[edit] Restricting the use of GBL

Although GBL is an unclassified drug in the United Kingdom, the risk to people's lives is being recognised on the London Gay Scene, where use is more prevalent than other parts of the country. Vauxhall, home to the majority of London's after-hours underground gay clubs, has witnessed an unprecedented number of collapses and death. At the end of 2006, a campaign began to reduce the number of people using GBL in the area. The effects of this campaign are yet to be seen.