Synthesis of haloenones and aryl or alkyl substituted enones or alkenes

A method for the production of an alkene or enone, comprising the steps of:

• reacting an alkyne or alkynol of the formula (IA) or (IB), respectively,:
• ##STR29## wherein R.sup.10 is optionally substituted alkyl or aryl;
• R.sup.1 is hydrogen or an optionally substituted alkyl or aryl group;
• and R.sup.2 is an optionally substituted aryl group;
• or R.sup.1 and R.sup.2 combine to form a cyclic group of the formula ##STR30## in which R.sup.1 ' is optionally substituted methylene and R.sup.2 ' is methylene and R.sup.4 is alkyl, O, cycloalkyl, cycloaryl, heterocycloalkyl or heterocycloaryl, with N--X.sup.1 -succinimide, in which X.sup.1 is bromine or iodine, in the presence of a catalytic amount of silver salt in an appropriate solvent under conditions satisfactory to produce a haloalkyne or haloalkynol of formula (IIA) or (IIB):
• ##STR31## and then producing a haloalkene or haloenone of formula (IIIA) or (IIIB):
• ##STR32## wherein X.sup.2 is bromine or iodine, by reacting said haloalkyne or haloalkynol of formula (IIA) or (IIB) (a) with N--X.sup.2 -succinimide or (X.sup.2).sub.2 in the presence of a catalytic amount of (hydroxy(tosyloxy)iodo)benzene or p-toluene sulfonic acid, or (b) with I.sub.2 /I.sub.2 O.sub.5, in which case X.sup.2 is iodine, under conditions satisfactory to produce a haloalkene or haloenone of formula (IIIA) or (IIIB).