1,4-Dienes, vinyl ethers, allyl ethers, allyl thio ethers, and propenethiolates were metalated by BuLi in the presence of an activator such as KOCMe3. Since the solvent, the counter-ion, or the temp. may be varied before subsequent treatment with an electrophile, the crit. ratio of direct vs. vinylogous attack (substitution at the a- or g-position, resp.) can be adjusted within large limits. Stereoselectivity was also achieved. [on SciFinder (R)]