Electrophilic Addition of Halogenes and Hydrogen Halides to Homologs of
1-Halogeno-3-buten-1-ynes

  1-Halogeno-3-methyl-3-buten-1-ynes add bromine at the doble bond and at position 1,4.

  The reaction of 1-bromo-3-methyl-3-buten-1-yne with clorine is complicated by chlorination in the methyl group and reduction of the bromine atom at thew triple bond.

  The addition of hydrogen bromide and iodide to 1-chloro-3-methyl-3-buten-1-yne and of hydrogen iodide to 1-chloro-3-penten-1-yne takes place with stereospeciphic fixation of the proton at the first acetylenic carbon atom in the trans position with the formation of the dihalides of cis-dienes.

  In the reactions of 1-chloro-3-penten-1-yne with hydrogen bromide and 1-bromo- and 1-iodo-3-alken-1-ynes with hydrogen halides full or partial reduction of the halogen at the triple bond occurs.