Describe in detail experiments which you could use to establish which of the isomers gives rise to the spectrum.
Answer
Describe in detail experiments which you could use to establish which of the isomers gives rise to the spectrum.
Answer
Answer
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The compound 2-bromo-2,3-dimethylsuccinic anhydride can exist as one of two isomers - one with methyl groups cis and one with methyl groups trans. The 1H NMR spectrum of one of the isomers of 2-bromo-2,3-dimethylsuccinic anhydride is given below. The spectrum consists of a quartet (1 proton) at d 2.8, a doublet (3 protons) at d 0.9 and a singlet (3 protons) at d 1.6 ppm. Describe in detail experiments which you could use to establish which of the isomers gives rise to the spectrum. Answer |
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The compound 1-bromo-2,3-dimethyl-2-pentene can exist as either an (E) or a (Z) stereoisomer. The 1H spectrum of one of the isomers of 1-bromo-2,3-dimethyl-2-pentene is given below. The spectrum consists of a quartet (2 protons) at d 2.8, a triplet (3 protons) at d 0.9 a singlet at d 3.5 for the -CH2-Br group and two singlets at d 2.1 and 2.5 for the -CH3 groups. Describe in detail experiments which you could use to establish which of the isomers gives rise to the spectrum. Answer |
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Given below is the basic spectrum and two difference NOE experiments on the cephalosporin molecule [1]. The large arrows indicate positions of saturation. Describe how the two difference spectra were obtained and what information can be obtained from the spectra. The numbers (in %) on the structure are the results from a number of NOE experiments. Are these values consistent with the structure as drawn ? Answer |
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