| 摘要 |
1,245,071. 5-Alkenyl-2-norbornenes. ESSO RESEARCH & ENG. CO. 3 Feb., 1969 [4 March, 1968], No. 5709/69. Heading C5E. 5-Alkenyl-2-norbornenes are prepared by reacting cyclopentadiene with a 4-alkyl-1,3- butadiene which contains a major proportion of the cis-isomer, in a molar ratio of cis-4-alkyl- 1,3-butadiene : cyclopentadiene of at least 1:1 and at a temperature of 100-275‹ C. Preferably at least 90% of the 4-alkyl-1,3-butadiene is in the cis-form, and the molar ratio of reactants is from 2:1 to 5:1. Examples describe the preparation of 5-propenyl-2-norbornene by reacting 1,3-cyclopentadiene with cis-piperylene. The cyclopentadiene may be charged as its dimer which readily dissociates at process temperatures into the monomer. The reaction may be effected with or without a solvent. |
