SOLVENT EFFECTS AND NUCLEOPHILE COMPETITION IN REACTIONS OF 3-CHLORO-3-METHYL-1-BUTYNE

The title compound reacts at 25° with (aqueous) alcohols in the presence of base via second-order kinetics (first order each in halide and base) and with rates related to the dielectric constant (water content) of the solvent but only slightly affected by ordinary salt effects or by the nature of the alcohol used. The reactions produce t-propargylic ethers in satisfactory yield from methanol and ethanol. Use of aqueous isopropyl or t-butyl alcohol results in hydrolysis, elimination, and rearrangement to the carbinol, enyne, and chloroallene, respectively. Relative rates of ether formation from alcohols follow (approximate): methyl (standard), 100; ethyl, 45; isopropyl, 4; t-butyl, 0. Unlike alcohols, amines of all types are excellent nucleophiles and lead to amino products in good yield. The reactions with amines are catalyzed by traces of either copper powder or cuprous chloride and are notably insensitive to steric factors. © 1969, American Chemical Society. All rights reserved.