Lithium 1, 8-diazabicyclo [5.4. 0] undec-7-en-6-ide (1) has underwent the insertion of carbon dioxide and the resulting lithium 6-carboxylato complex (2) transfered the carboxylato moiety to active methylene compounds (3) such as p-nitroacetophenone, acetophenone, p- methoxyacetophenone, and s-benzylthioacetate under mild conditions.
