Reactions of N-, P-, and S-nucleophiles with methyl propiolate

1.	In contrast to the case of cyanoacetylene, the nucleophilic addition to methyl propiolate takes place with the preferential or exclusive formation of trans products, if steri cally hindered N-nucleophiles and N-, P-, S-nucleophiles with a weakened +M-effect of the central heteroatom are used.
2.	For the qualitative evaluation of the stereochemical result of the nucleophilic addition reaction to activated acetylenes, it was proposed to use the R constant of the activating substituent.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 382–391, Februar, 1988.