Makefile execute phonytargets of a file only if file does not exists

Is there any way I can only execute the phony dependency of a file if this file does not exist?

If the file has no phony dependency it works and only executes the content of this rule. But if I add a phony target as dependency it keeps executing the dependency rule and the rule of generating the existing file.

I simplified my Makefile so you can see my problem:

 
.PHONY: phonytarget all clean

all: $(CURDIR)/a.a
    @echo done

$(CURDIR)/a.a: phonytarget
    @touch $@

phonytarget:
    @echo what the heck is wrong with you