Acetone is the major product in: I) H3C−CH=CH2H+/H2O−−−−−→ II) H3C−C≡CHHg2+/H2SO4 (aq.)−−−−−−−−−−−→ II) H3C−C≡CHBH3, THF−−−−−−−→H2O2/OH−