Crystal and molecular structure of 1-lithio-3,6-diethoxy-2,5-dimethyl-1,2-dihydropyrazine, the lithiated bis-lactim ether of the diketopiperazine from alanine

Crystals of a racemic sample of the title compound, grown from a tetrahydrofuran (THF) solution, contain dimeric aggregates of homochiral moieties in which the two lithium atoms and the two negatively charged nitrogens of the heterocycle form a four-membered ring; one lithium is co-ordinated by a single THF molecule, the other by two.