Altkali salts of 1,3,3-trisubstituted propynes and use of these organometallic compounds in syntheses

With the decrease of delocaliring ability of substituents in salts f of 1,3,3-trisubstituted propynes the structure of carbanions shifts from prop* gglic towards allenylic type. Such a changeover of structure - from propgyljc to purely allenylic - is perticularly developed for CIP of salts 1. Variabon in both structure of carbanions in & and ionic association in solutions of 1 exerts a marked effect on regioselectivity of their dkylation, leadin to mixtures of acetylenic and allenic products. Innuence of the nature of agylatin ent on regioselectivity of alkylation of f is essential. Protonation and trimet&$lation of salts 3 lead exclusively to deic products.