Nachweis eines cyclopropens bei der darstellung eines alkylidencyclopropans.

Synthesis of Methylene- and Alkylidenecyclopropane Derivatives

“…209 Also monochlorocyclopropanes give the same process. 210,211 The same process with 1-methyl-2-chlorocyclopropane 154 in the presence of a crown ether has led to the formation of cyclopropylmethylenecyclopropane 155 in good yields (Scheme 50). 212 When the elimination is carried out in the presence of a nucleophile (alcohol, thiol, or amine) the formation of the methylenecyclopropane is accompanied by nucleophilic substitution.…”

“…When n = 1 the primary endo -methylenecyclopropane rearranges to the exo -methylenecyclopropane 153 with ring contraction (Scheme ) , …”