Terminal alkynes RC CH [R= PhCO, PhCH2OCO,(CH3) 2CHCH2OCO, Et2NCO,(EtO) 2P (O), PhCH2, H2C CH CH2, and Ph CH (OH)] may be prepared in satisfactory yield in a one-pot process by reaction in THF at− 78° C of the titled reagent with electrophiles followed by acidic workup with dilute HCl.