Summary: Dialkylboryl-alkylidenetriphenylphosphoranes 1 react with deuteromethanol to deu--terated ylides a, which lead by Wittig reaction to specifically deuterated olefins 7.-Re- _ action of 1 with bromine gives rise to formation of the phosphonium salts 2, which by treat-- ment with butyllithium are converted into the brominated ylides 8. Carbonyl olefination-with 8 yields the vinyl bromides 10.--
