Abstract Three dihaloadamantanes [ie, 2-bromo-1-(chloromethyl) adamantane (1), 1- (bromomethyl)-2-chloroadamantane (2) and 2-bromo-1-(bromomethyl) adamantane (3)] were synthesized, and their corresponding ring-closing reactions, performed by using Na metal or alkyllithium reagents, were studied. Compound 1 reacted with Na in toluene or in tetraglyme to afford 1, 2-methanoadamantane (4) as the major product. However, the ...