Demanded changes after Mike leaves cul-de-sac (4,3)
I believe the answer is:
dead end
'cul-de-sac' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
(Other definitions for dead end that I've seen before include "that's leading nowhere" , "A blind alley, sounds moribund" , "going nowhere" , "Blind alley or situation without prospects" , "Blind alley, cul-de-sac" .)