Process for the production of polyunsaturated compounds

A process which comprises

• a. forming an intermediate complex by combining, in an organic solvent, at temperature of from -40.degree. to +100.degree.C and in the presence of at least one antioxidant,
• i. a molar equivalent amount of a copper(I) halide or copper(I) cyanide,
• ii. from 1 to 1.5 molar equivalent amount of an ethynyl reactant of the formula:
• R.sup.1 C.tbd.CH
• in which R.sup.1 is hydrogen, alkyl of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkynyl of 2 to 12 carbon atoms, polyalkenyl of up to 12 carbon atoms, polyalkynyl of up to 12 carbon atoms, or said alkyl, alkenyl, alkynyl, polyalkenyl or polyalkynyl substituted by tetrahydropyranyloxy, tri(lower alkyl)silyl, hydroxy, carboxy, carbo(lower alkoxy), carboxamide or a group of the formula:
• ##EQU16## in which each of R.sup.I and R.sup.II is alkyl of 1 to 5 carbon atoms;
• and iii. from 1 to 1.5 molar equivalent amount of 1,8-diazabicyclo[5.4.0]undecene or 1,5-diazabicyclo[4.3.0]nonene, and
• b. combining with said complex at least a molar equivalent amount of a second reactant of the formula:
• XR.sup.2
• in which X is chloro, bromo or iodo and
• R.sup.2 is a mono- or poly-unsaturated aliphatic hydrocarbon of up to 12 carbon atoms, unsubstituted or substituted by tetrahydropyranyloxy, tri(lower alkyl)silyl, hydroxy, carboxy, carbo(lower alkoxy), carboxamide or a group of the formula:
• ##EQU17## wherein each of R.sup.I and R.sup.II is alkyl of 1 to 5 carbon atoms;
• said R.sup.2 being selected so that X is comprised in said XR.sup.2 on a terminal 3-X-prop-1-en-1-yl or 3-X-prop-1-yn-1-yl group, thereby coupling the ethynyl group of ethynyl reactant with the prop-1-en-1-yl or prop-1-yn-1-yl group of said second reactant to form a compound of the formula:
• R.sup.1 C.tbd.CR.sup.2
• in which R.sup.1 and R.sup.2 are as defined above.