Behavior of 3?, 4?, and 5 ? alkenyl halides in condensation reactions with alkyl halides in presence of magnesium

Abstract

1. In a study of the reactions of methylmagnesium bromide with 4-bromo-4-phenyl-1-pentene and with 4-promo-2,4-dimethyl-1-pentene we have obtained further confirmation of the inactivity in condensation reactions of alkenyl halides having a γ-double bond. 2. In a study of the condensations of 5-chloro-5-methyl-1-hexene with methylmagnesium bromide, of 5-bromo-5-methyl-1-hexene with allylmagnesium bromide, and of 4-pentenylmagnesium bromide with 5-butyl-5-chlorononane, with 4-chloro-4-propylheptane, and with 2-chloro-2-methylpropane, we have shown that alkenyl 3. Taking the condensation of 6-bromo-6-methyl-1-heptene with methylmagnesium bromide as example, we have shown that a double bond in the e-position with respect to the halogen has no longer any effect on the activity of the halogen compound, which reacts with Grignard reagents and gives the same yields as the corresponding alkyl halides. It has thus been shown that the alternation of inactivity (a- and γ-double bonds) with activity (very high for a β-double bond and low when the double bond is in the δ-position) is interrupted when the double bond reaches the δ-position. 4. The following substances were synthesized for the first time: 2-methyl-6-hepten-2-ol, 6-bromo-6-methyl-1-heptene, 6,6-dimethyl-1-heptene (by two methods), 6,6-dipropyl-1-nonene, and 6,6-dibutyl-1-decene. Raman spectra have been determined for some of the compounds prepared.