CHEM 2301 Lecture Notes - Lecture 42: Geminal, Wavenumber, Infrared Spectroscopy

Hi could you help me with this problem please?

The following spectroscopic data were obtained for an organic compound:
i. MS (relative abundance in parentheses): M⁺ = 86 ; signals at 29 (92) and 41 (100) among others
ii. IR (cm^-1): 3100 (weak sharp), 2970 (medium sharp), 2850 (medium), 1650 (weak sharp), 1100 (strong sharp)
iii. H¹ NMR :
Signal A at 4 ppm (3H, triplet),
Signal B at 3.53 ppm (2H quartet),
Signal C at 4.01 ppm (2H, doublet),
Signal D₁ at 5.25 ppm (1H, doublet)
Signal D₂ at 5.28 ppm (1H, doublet)
Signal E at 5.95 ppm (1H, multiplet)
note: signal D₁ and D₂ are two separate signals, right next to each other, each with integration of 1H and multiplicity of "doublet"
iv. C13 NMR (proton \-decoupled):
Signal I at 14 ppm,
Signal II at 64 ppm,
Signal III at 71 ppm,
Signal IV at 115 ppm
Signal V at 135 ppm.

Please answer the following:
A. Draw the most likely structure of this compound. Show all of the hydrogens in the structure.

B. Label all H's with the signal letter that the Hproduces in the H¹ NMR spectrum. Explain why each H¹ NMR signal has the chemical shift specified. Be specific about each group of chemically-equivalent protons in this particular compound (not in general)

C. Explain multiplicities for EACH and EVERY H¹ NMR signal (i.e. what is each signal being split by?). Make sure to explain why there are actually two signals near 5.25 ppm (signals D₁ and D₂) that are both doublets, instead of a single signal that would be a doublet of doublets. Note: The hydrogens producing signals D₁ and D₂ are actually coupled to each other, but the coupling constant is so small that it is hard to see any coupling of D₁ with D₂ in the spectrum. The info for D₁ and D₂ above assume that J for these two protons is 0 Hz. Also assume that long-range coupling is not observed.

In estrification lab, the ester was Methyl Benzoate,

((lap report of estrification (methyl Benzoate) NMR spectroscopy )

Q\ Analyze the Peaks of H-NMR spectroscopy

indicating the number of different hydrogen atoms and their

surroundings in the molecule.

Use the table below to fill out the details from the NMR spectroscopy figure .

this is a post lap of Methyl Benzoate