ɪf ɪɾ ɪz nˈɛsᵻsɚɹi tə ɹᵻdˈuːs wˈʌn kˈɑːɹbənˌaɪl ɪnðə pɹˈɛzəns ʌv ɐnˈʌðɚ, ðə kˈɑːmən kˈɑːɹbənˌaɪl pɹətˈɛktɪŋ ɡɹˈuːps mˈeɪ biː ɛmplˈɔɪd.
If it is necessary to reduce one carbonyl in the presence of another, the common carbonyl protecting groups may be employed.