1.The dehyration of α,α-dimethylcyclopropanemethanol over acidic catalysts goes considerably more readily than the opening of the cyclopropane ring of the 2-cyclopropylpropene formed. Over alumina and calcium phosphate almost pure 2-cyclopropylpropene is obtained in yields of 60 and 78% respectively.2.The 2-cyclopropylpropene formed by the dehydration of the alcohol is isomerized into cis-2-methyl-1,3-pentadiene and 2-methyl-1,4-pentadiene. The latter is converted into cis-2-methyl-1,3-pentadiene, which is further isomerized into the trans for