METHOD OF PRODUCING L-LACTIDE Russian patent published in 2012 - IPC C07D319/12 

FIELD: chemistry.

SUBSTANCE: method of producing L-lactide involves a step for oligomerisation of a lactic ester in alkyl ether of lactic acid oligomers in a current of inert gas at atmospheric pressure and high temperature, and a step for depolymerisation of the alkyl ether of lactic acid oligomers at high temperature in a vacuum, carried out in the presence of the same catalyst - tin (IV) compounds, wherein the catalyst used at the oligomerisation and depolymerisation steps is tin tetrachloride.

EFFECT: high rate of oligomerisation of alkyl lactate and depolymerisation of alkyl ether of the oligomer, high output of L-lactide.

4 cl, 9 ex