The present invention relates to a process for preparing a (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound of the following general formula (3-Z): wherein Y represents a halogen atom, Ar represents, independently of each other, an aryl group, and R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.1 and R.sup.2 may form together a divalent hydrocarbon group, R.sup.1-R.sup.2, having 2 to 10 carbon atoms, the process comprising: subjecting a (7Z)-11-halo-1,1-dialkoxy-7-undecene compound of the following general formula (1-Z): wherein X.sup.1 represents a halogen atom, and R.sup.1 and R.sup.2 are as defined above to a phosphonium salt formation reaction with a phosphine compound of the following general formula (2): wherein Ar is as defined above to form the (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound (3-Z).

##STR00001##

The present invention relates to a process for preparing a (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound of the following general formula (3-Z): wherein Y represents a halogen atom, Ar represents, independently of each other, an aryl group, and R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.1 and R.sup.2 may form together a divalent hydrocarbon group, R.sup.1-R.sup.2, having 2 to 10 carbon atoms, the process comprising: subjecting a (7Z)-11-halo-1,1-dialkoxy-7-undecene compound of the following general formula (1-Z): wherein X.sup.1 represents a halogen atom, and R.sup.1 and R.sup.2 are as defined above to a phosphonium salt formation reaction with a phosphine compound of the following general formula (2): wherein Ar is as defined above to form the (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound (3-Z).

##STR00001##

The present invention relates to a process for preparing a (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound of the following general formula (3-Z): wherein Y represents a halogen atom, Ar represents, independently of each other, an aryl group, and R.sup.1 and R.sup.2 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R.sup.1 and R.sup.2 may form together a divalent hydrocarbon group, R.sup.1-R.sup.2, having 2 to 10 carbon atoms, the process comprising: subjecting a (7Z)-11-halo-1,1-dialkoxy-7-undecene compound of the following general formula (1-Z): wherein X.sup.1 represents a halogen atom, and R.sup.1 and R.sup.2 are as defined above to a phosphonium salt formation reaction with a phosphine compound of the following general formula (2): wherein Ar is as defined above to form the (4Z)-11,11-dialkoxy-4-undecenyltriarylphosphonium halide compound (3-Z).

##STR00001##

Disclosed are a salt represented by formula (I), an acid generator, and a resist composition comprising the same: ##STR00001##
wherein R.sup.1 and R.sup.2 each represent a hydroxy group, *OR.sup.10, *O-L.sup.10-COOR.sup.10; L.sup.10 represents an alkanediyl group; R.sup.10 represents an acid-labile group; R.sup.4, R.sup.5, R.sup.7 and R.sup.8 each represent a halogen atom, a haloalkyl group or a hydrocarbon group; A.sup.1 and A.sup.2 each represent a hydrocarbon group, the hydrocarbon group may have a substituent, and CH.sub.2 included in the hydrocarbon group may be replaced by O, CO, S or SO.sub.2; m1 represents an integer of 1 to 5, m2 and m8 represent an integer of 0 to 5, m4, m5 and m7 represent an integer of 0 to 4, 1m1+m75, 0m2+m85; and Al.sup. represents an organic anion.