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Borohydride Reduction of a Ketone

Results
1. Draw a three-dimensional structure of the stereoisomer formed in the reaction. Name the compound. meso-Hydrobenzoin

2. Include other results as suggested by your data.
* The attached IR and NMR spectroscopy data.
* The melting point that ranges from 135.6-137.90C.

Spectroscopic Analyses Data tables
IR Spectroscopy

Hydrobenzoin
Peaks (cm-1)| Stretches| Intensity|
3332 (cm-1)| O—H stretch| Strong and broad|
3027| C—H stretch| Medium and Weak|
14450-1620 (cm-1)| Benzene ring stretch| Medium|

Benzil
Peaks (cm-1)| Stretches| Intensity|
3062 (cm-1)| Csp2—H stretches| Strong |
1677 (cm-1)| C==O stretch | Strong|
1445| Benzene ring stretch| Strong|
936| C—H bend| Strong|
874cm-1)| Csp2—H stretches| Strong|

Dioxolane
Peaks (cm-1)| Stretches| Intensity|
3062 (cm-1)| C—H stretch| Medium to Weak|
2000-1500 (cm-1)| C==O stretch | Strong|

Percentage yield of hydrobenzoin
0.74g Benzil210.23gmol1mol hydrobenzoin1 mol benzil 214.26g hydrobenzoin1 mol hydrobenzoin=0.74g % yield=0.66g0.74g×100=89%

Percentage yield of dioxalane
0.29g hydrobenzoin216.26 gmol 1 mol hydrobenzoin1 mol benzoin 256.94g dioxalne1 mol dioxalane=0.34g % yield=0.16g0.34g×100=47%

Questions
1. Problem 2 from page 311 of your laboratory text.
The broad peak at about 3300 in the IR corresponds to the O—H group in the product. The peaks to the right of aro0und 3000 are C—H related, those about 1599 are C—H bends, and the peaks at 1000-1350 are C—O related. The most plausible product seems to be cyclohexanol with a molecular formula of C6H12O.

2. Describe the stereochemical relationship between each pair of isomers. (a)

Same
(b)
Diastereomers

3. How many methoxy signals are expected in the NMR spectrum of the following compound? Explain your answer.

There are 2 singlets because there are no...
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