cis-1-Bromo-1-propene

Uses

cis-1-Bromo-1-propene is generally used as a reactant in organic synthesis.

Application

Used as a precursor for (E)- or (Z)-1-propenyllithium and 1-propenylmagnesium bromide, and a reagent for electrophilic propenylation.

General Description

cis-1-Bromo-1-propene is an aliphatic olefin. Oxidation of cis-1-bromo-1-propene by toluene dioxygenase has been reported.

Synthesis

(Z)- and (E)-1-propenyl bromides can be obtained through spinning band distillation of the commercially available mixture of isomers (Z/E = 70/30). However, the (E)-isomer can only be obtained with difficulty due to thermal isomerization to the (Z)-isomer. Pure (Z)-1-propenyl bromide can be prepared by bromination of (E)-crotonic acid followed by bromodecarboxylation of the resulting erythro-2,3-dibromobutanoic acid in the presence of Triethylamine or Diisopropylethylamine at 40 °C (eq 1). (E)-1-Propenyl bromide can be obtained in 98% purity by treatment of the commercially available mixture of isomers (Z/E = 70/30) with Sodium Hydroxide in n-BuOH at reflux until no (Z)-1-propenyl bromide is detected by GLC.

storage

Stored in a refrigerator to inhibit thermal and acid-catalyzed isomerization. Avoid breathing vapor and contact with skin and eyes. Use in a fume hood.