Novel ene trimerization of 1-phenylcyclopropene.
1-Phenylcyclopropene (1) was synthesized by treatment of 1,1,2-tribromo-2-phenylcyclopropane (2) with 2.5 equiv of methyllithium followed by protonation. Compound 1 underwent ene dimerization to form ene dimer 5 followed by ene reaction with monomer 1 (enophile) to give an ene trimer 6. Both of these two ene reactions derived endo transition states. In the meantime, the [2+2] adduct, trans-1,2-diphenylbicyclo[3.1.0.0(2,4)]hexane (7), was also formed. When the adduct 7 was heated at THF refluxing temperature, 1,2-diphenylcyclohexa-1,4-diene (8) was obtained. Compound 8 was treated with DDQ to yield o-diphenylbenzene.
Lee
Gon-Ann
GA
Department of Chemistry, Fu Jen Catholic University, Hsinchuang, Taipei 24205, Taiwan, Republic of China. chem1010@mails.fju.edu.tw
Chang
Chih-Yi
CY
D003521:Cyclopropanes / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011760:Pyrrolidinones / Q000737:chemistry; D013237:Stereoisomerism
D003521:Cyclopropanes; D011760:Pyrrolidinones; C496115:talaroconvolutin A