1-Alkenyl chlorides, bromides or iodides, e.g., cis-1-chloro-1-octene, can be obtained with very high cis selectivities by Wittig reactions with a-chloro, a-bromo and a-iodo ylides derived from (2-MeOCH2C6H4)3P. The corresponding a-methoxy substituted ylid ...
1993