Abstract: A process for the manufacture of disubstituted (N-cyanoimido)carbonate of the formula: ##STR1## in which R.sup.1 and R.sup.2 are the same and are alkyl radicals of 1 to 6 carbon atoms or phenyl radicals, or R.sup.1 and R.sup.2 are joined to form an ethylene or propylene chain which is optionally substituted by 1 or 2 alkyl radicals each of 1 to 3 carbon atoms, by reaction of a disubstituted imidocarbonate of the formula: ##STR2## with cyanamide, characterized in that the reaction is conducted in a two phase system containing water and a water-immiscible organic solvent.

Abstract: The disclosure relates to .omega.-aryl substituted .omega.-nor prostaglandin analogues bearing an oxygenated function at C-10, such as a hydroxy radical, or a 9,10- or 10,11-epoxide. A typical compound is 16-(3-chlorophenoxy)-9.alpha.,10.beta.,11.alpha.,15.alpha.-tetrahydroxy-17 ,18,19,20-tetranor-5-cis,13-trans-prostadienoic acid. Also disclosed are chemical processes for the manufacture of said compounds, pharmaceutical and veterinary compositions containing said compounds, and a method of achieving luteolysis in mammals by the use of such compounds.