P shows a strong peak in its IR spectrum at 1700 cm, 300-2850 cm-1. The H NMR spectral data of P are given here. What kind of structure can you propose?
(singlet, ppm=1.0, H ratio =9) (doublet, ppm=1.3, H ratio =3) (quartet, ppm=3.5, H ratio =1)
HELP PLEASE. WHERE DO I START?
(singlet, ppm=1.0, H ratio =9) (doublet, ppm=1.3, H ratio =3) (quartet, ppm=3.5, H ratio =1)
HELP PLEASE. WHERE DO I START?
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The mass peak being an equal doublet separated by 2 mass units is strong indication that there is Bromine on account of 2 isotopes Br-79 and Br-81 in equal abundance (natural)
IR tells you there is a C=O group. 3000-2850 tells you there are C-H bonds and probably not aromatic or vinylic C-H. (These would be above 3000 cm-1)
NMR singlet at 1.00 ppm indicates -C(CH3)3 group (t-butyl group)
Doublet indicates splitting by a single adjacent C-H and Quartet indicates splitting by adjacent CH3
The position of the CH (quartet) indicates it is adjacent to the C=O and to a C-Br (bcoz it is shifted quite downfield) and it is split by an adjacent CH3 group (which is why it is a quartet)
Piecing the puzzle:
You have all the fragments -- t-butyl, a C=O, CH3, CH(Br) and a good guess would be
(CH3)3C-CO-CH(Br)CH3
The molecular formula is C7H13OBr which is (84 + 13 + 16 + 79 = 192
I am pretty confident it is Me3CC=OCH(Br)CH3)--it is consistent with the NMR, IR and MS
IR tells you there is a C=O group. 3000-2850 tells you there are C-H bonds and probably not aromatic or vinylic C-H. (These would be above 3000 cm-1)
NMR singlet at 1.00 ppm indicates -C(CH3)3 group (t-butyl group)
Doublet indicates splitting by a single adjacent C-H and Quartet indicates splitting by adjacent CH3
The position of the CH (quartet) indicates it is adjacent to the C=O and to a C-Br (bcoz it is shifted quite downfield) and it is split by an adjacent CH3 group (which is why it is a quartet)
Piecing the puzzle:
You have all the fragments -- t-butyl, a C=O, CH3, CH(Br) and a good guess would be
(CH3)3C-CO-CH(Br)CH3
The molecular formula is C7H13OBr which is (84 + 13 + 16 + 79 = 192
I am pretty confident it is Me3CC=OCH(Br)CH3)--it is consistent with the NMR, IR and MS