500-ml flask equipped with mechanical stirrer, Dry Ice condenser, nitrogen inlet-outlet, and an addition funnel. The addition of methyl iodide to lithium was performed at ice-salt temperature in about 2 hr. After an additional 2 hr all lithium had reacted. The methyllithium solution was cooled in an acetone-Dry Ice bath and a solution of a 60:40 mixture of ethyl 2,2-dimethyl-3vinyl-and ethyl 3-ethylidene-2,2-dimethylcyclobutaneacetate (19.6 g, 0.1 mol) in anhydrous ether (25 ml) was added dropwise with rapid stirring. After addition was complete, the mixture was allowed to warm to room temperature and stirred in a nitrogen atmosphere overnight. The reaction slurry was poured onto 300 g of crushed ice containing 100 ml of concentrated ammonia. The mixture was stirred rapidly for 1 hr. The ether layer was separated and the aqueous layer was extracted with 2 X 100 ml of ether. The combined ether solutions were washed with water and dried over anhydrous sodium sulfate. Removal of ether

Aus den Dicyan‐benzolen (Ia)‐(Ic) erhält man mit Azid und Alkoholat die Bis‐Anionen (IIa)‐(IIc) bzw. auch die entsprechenden Ammoniumsalze.