TRIMETHYLSILYL- UND HALOGENSUBSTITUIERTE 2-METHYL-1-PENTENE

Article abstract of DOI:10.1016/0022-328X(84)85139-6

2-Methyl1-pentenes D, with Cl and/or Br substituted in positions 1 and 5 respectively, were synthesized for the first time, with 2-acetyl-γ-butyrolactone as the starting compound, and they reacted after either metallation with butyllithium or transformation into Grignard compounds with chlorotrimethylsilane to give the different trimethylsilyl- and halogen-substituted 2-methyl-1-pentenes L, M, N and P.Because of the Wittig reactions in the steps 3 + A <*> B and E + A <*> D, all the pentenes were obtained in their E/Z isomeric mixtures.The assignment of the NMRspectra to the E and Z form was made possible from investigating Van der Waals and nuclear Overhauser effects (NOE) in the 400 MHz spectra.Transformation of D into Grignard compounds is highly dependent on the character of the halogen in positions 1 or 5.