Question

NMR Help please!

Based on the molecular formula and the UN/DBE you calculated, check all the functional group that could be present in compound B? Examine the IR spectrum provided for Compound B. The peaks below 1500 cannot be used to make any structural assignments because they are i fingerprint region. There are the two important peaks in this IR spectrum, What is each peak most likely due to? Earlier, using the molecular formula and the UN/BE, you came up with a list of functional groups that could be present in compound A. Now using the IR data you should be able to narrow this list down. Below, check all the functional groups that could be present in compound B. Examine the 13 C spectrum of Compound B. compare the number of signals in the spectrum and the number of carbons from the molecular formula for compound B. Which of the following is true? all the carbons are non-equivalent there is one set of four equivalent carbons there are two separate sets of equivalent carbons Evaluate the spectrum for Compound A based on what you already know from the UN/DBE and IR spectrum. Is the 13 C spectrum consistent with the presence of an alcohol functional group? Examine the 1 H spectrum of Compound B. Below is a table summarizing the spectral data. Using that data, assign each peak to the type of alkyl group. Based on the IR spectrum you determined that there will be an alcohol functional group. Which signal in the 1 H spectrum is due to that OH? Based on the carbon spectrum you know that the molecule has a high degree of symmetry. Yet compound B has only on O. Therefore the OH group and the carbon that it is attached to have to belong in the plane of symmetry. Which 1 H signal is due to the hydrogen that is on the same carbon as the OH group? Examine signal D: it has an integration of 12. How many equivalent methyl (CH_3) groups are there in compound B? Based on the carbon spectrum you know that the molecule has a high degree of symmetry. Yet Compound B has only on O. Therefore the OH group and the carbon that it is attached to have to belong in the plane of symmetry. Which 1 H signal is due to the hydrogen that is on the same carbon as the OH group? Examine signal D: it has an integration of 12. How many equivalent methyl (CH_3) groups are there in compound B? Now you need to arrange the methyl groups in such a way that each of them is bound to a carbon that only has one proton on it. What is the name of this alkyl fragment? ethyl group n-propyl group isopropyl group tert-butyl group Propose a structure for compound B. Once you have a structure, it is always helpful to go back throught the spectral data and make sure that the structure you came up is consistent with ALL of it.

Answer 1

groupe tha cold be present in conpound B? □ benzene ring akyne ring akene Pesk 1: 3400 m Pusk 2:2950 H er NH C-Hisaal O COorCN Estler, using the mcleculer forms and he UN/DBE. you came up with a ist of functionel grouce thet could be present in compound A, Now uaing the R dots youatuld be able to s iat down Below, ceck al the funcional grupe tacodd be present in compound B ro aldohyde carboayle acid opondo alkyne benone ting Compere the number of compound B. Wich of the tolowing ia true? s in the spetrum and the number ofcartens rom the moleauler fomda r O alre cartons are nonequivalent thiee is one set ef lor equivalent catens thore are two separato sots of equivalart carbons Evaluate the spectrun for Conçound A bssed on whet you aready know from the UN DBE and IR spectrum. Is he sprum cona stent with te precance of an slcoholtuntional group? ppm integrationting A 3.60 tH biplet mutplot 100 2H D 0.DD 2H 8ssed on he lR spectrum you determined tat tere wil b" en ย๒ho functonel group Which sgnal in the H spectrum is due to that CH Based on the carbon specrum you knon that the moiecule has a high d is attached to heve to telong in the plane of bymmetry Which Hsignal is due to the hydrogen that is on the same carbon as he CH group? e Compound B has cnly on Thereloe the CH group and the carbon tha c Scrol dowm Examino cignal O thos an intogration of 12. How many squivalont mothyl(CHa) groups aro thoro in compound B? Now ycu nod lo arango the mothyl groupe in such a way that ach oftem is bound to a caten nat aniy hai one proon on it Hint: Calculate how many carbons and hydrogens ycu havent used yet What is the name of thie alkyl ragment? O uhyl group O n propyl group

HO 2,4-dimethylpentan-3-ol Chemical Formula: C7H16O Molecular Weight: 116.2040 ChemNMR H Estimation 0.98 0.98 1.92 3.20 0.98 92 HO 4.60 0.98 5 4 2 PPM