Propiolactone

Due to the tension of the four-membered cycle, propiolactone is a highly reactive compound, which is characterized by reactions with the opening of the cycle.

When heated, propiolactone polymerizes with the formation of linear polyesters [—OCH ₂ CH ₂ C (O) -] _n , the same polymerization can be carried out under mild conditions under the influence of various catalysts.

The pyrolysis of propiolactone in the gas phase leads to the formation of ethylene and carbon dioxide.

Being a cyclic ester , propiolactone is an electrophile, the direction of the nucleophilic attack depends on the nature of the nucleophile: hard nucleophiles attack propiolactone at the carbonyl carbon atom, soft ones at oxymethylene carbon:

Propiolactone hydrolyzes with the formation of β-hydroxypropionic acid, under neutral conditions and with acid catalysis, the interaction of propiolactone with alcohols and phenol leads to the formation of β-hydroxypropionic acid ethers , the reaction with thiophenol under these conditions proceeds similarly:

(CH ₂ CH ₂ O) CO + RXH${\displaystyle <span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">\to </span></span>}$ {\ displaystyle \ to}   RX (CH ₂ ) ₂ COOH

X = O, S

The interaction of amines with propiolactone in acetonitrile leads to the formation of β-aminopropionic acid as derivatives (with ammonia, ethylamine, aniline):

(CH ₂ CH ₂ O) CO + R ¹ R ² NH${\displaystyle <span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">\to </span></span>}$ {\ displaystyle \ to}   R ¹ R ² NH (CH ₂ ) ₂ COOH,

and amides of β-hydroxypropionic acid:

(CH ₂ CH ₂ O) CO + R ¹ R ² NH${\displaystyle <span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">\to </span></span>}$ {\ displaystyle \ to}   HO (CH ₂ ) ₂ CONR ¹ R ²

Propiolactone is prepared by the catalytic reaction of formaldehyde (CH ₂ O) with ketene (CH ₂ = C = O).

Propiolactone solutions and vapors have a strong bactericidal effect ; it is used in medicine for sterilization of blood , vaccines , enzymes and other biological preparations, as well as a fumigant .

• Lactones