15. Analytical Techniques:IR, NMR, Mass Spect

A chemist made what was thought to be compound A or B. How could coupling constants between Hₐ and H₆ be used to distinguish between the two isomers? [Hint: Draw a chair conformation of each.] A B

Draw the expected signal for a hydrogen with the following coupling constants. (b) Hₐ : δ 3.34 (Jₐ꜀ = 9 , Jₐ₆ = 4 )

Though it wasn't discussed, what coupling constant would you expect for Hₐ and H꜀ in the spectrum of trans-but-2-enoic acid in Figure 15.50? Justify your answer.

Sketch the signals you would expect to see for Hₐ in the molecule shown. The important coupling constants are given.

Sketch the signals you would expect to see for H₆ in the molecule shown. The important coupling constants are given.

Sketch the signals you would expect to see for H꜀ in the molecule shown. The important coupling constants are given.

(••) For the hydrogen(s) screened in blue, draw the signal you would expect to see in a ¹H NMR spectrum. At which chemical shift would the signal appear? (c)

(••) For the hydrogen(s) screened in blue, draw the signal you would expect to see in a ¹H NMR spectrum. At which chemical shift would the signal appear? (e)

(•) Predict the splitting pattern for each of the indicated hydrogens in Assessment 15.59. d