2-Chloropropionic acid is the chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the formula CH₃CHClCO₂H. This colorless liquid is the simplest chiral chlorocarboxylic acid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

, and it is noteworthy for being readily available as a single enantiomer.

Preparation

Enantiomerically pure (S)-2-chloropropionic acid is prepared from L-alanine

Alanine

Alanine is an α-amino acid with the chemical formula CH3CHCOOH. The L-isomer is one of the 20 amino acids encoded by the genetic code. Its codons are GCU, GCC, GCA, and GCG. It is classified as a nonpolar amino acid...

 via diazotization in hydrochloric acid

Hydrochloric acid

Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....

. Other α-amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

s undergo this reaction.

Reactions

Reduction of (S)-2-chloropropionic acid with lithium aluminium hydride

Lithium aluminium hydride

Lithium aluminium hydride, commonly abbreviated to LAH or known as LithAl, is an inorganic compound with the chemical formula LiAlH4. It was discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters,...

 affords (S)-2-chloropropanol, the simplest chloro-alcohol. This alcohol undergoes cyclization upon treatment with potassium hydroxide

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

, which causes dehydrohalogenation

Dehydrohalogenation

Dehydrohalogenation is an organic reaction from which an alkene is obtained from an alkyl halide . It is also called a β-Elimination reaction and is a type of elimination reaction....

 to give the epoxide

Epoxide

An epoxide is a cyclic ether with three ring atoms. This ring approximately defines an equilateral triangle, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in...

, (R)-methyloxirane.

Safety

In general, α-halocarboxylic acids and their esters are good alkylating agents and should be handled with care. 2-Chloropropionic acid is a neurotoxin.