STRUCTURE-REACTIVITY RELATIONSHIPS .2. STERIC EFFECT ON THE REACTIVITY OF 1-ETHOXY 3-TRIMETHYLSILYL 1-PROPYNE WITH SOME CARBONYL-COMPOUNDS

Structure-reactivity relationships between carbonyl compounds and 1-et hoxy 3-trimethylsilyl 1-propyne, were established. Reaction yield was used as a reactivity index. Yield% = 52.786 - 1.799 MM2 + 31.784 RM2/R M1 - 8.542 MM2/MM1 n = 17, r = 0.961, s = 8.569 RM2 and RM1 are the co ntributions of R2 and R1 respectively to the molar refraction of the m olecule. RM accounts for the size and the electronic aspect of the rad ical. MM2 and MM1 are the molar weights of R2 and R1 respectively. The y account for the size of the radicals. The model obtained accounted f or about 92% of the initial information and showed that steric and ele ctronic effects govern the reactivity of the studied compounds. Design of the transition state initially given was improved on the basis of the parameters included in the model.