Question

I need help understanding how to read an 13C NMR and answering the questions below.

C. Conversion of 2° Alcohols to Alkyl Halides 1. Write the equation for the conversion of 2-pentanol to three alkyl bromide products: two secondary and one primary. Under the products, write the name of the alkyl bromide. NaBr, H2SO4 2. Attach the 13C NMR spectrum for this reaction. a) How many peaks (unique carbons) would be present in the spectrum: for a rearranged alkyl bromide? for an unrearranged alkyl bromide? for a primary alkyl bromide? b) Based on the spectrum, how many peaks are present in the product? c) Which product(s) is (are) formed? d) On the spectrum, circle the peak that represents the carbon(s) attached to the halogen(s). 3. Write the equation for the conversion of 2,4-dimethyl-3-pentanol to two alkyl chloride products: one secondary and one tertiary. Under the products, write the name of the alkyl chloride. HCI, ZnCl2 4. Attach the 13C NMR spectrum for this reaction. a) How many peaks (unique carbons) would be present in the spectrum: for the secondary alkyl chloride? for the tertiary alkyl chloride? b) Based on the spectrum, how many peaks are present in the product? c) Which product(s) is (are) formed?

Answer 1

17 Conversion of 2 pentanod to two secondary altyl bromide of One primary allyl Bromide. to H₂ sou 20 carbocation Boy :01 ker sec.ally Bromide secondary Carbo carian (A) can undergo rearrangement as see-allyl Gromidre secondary allyl carbocation would forry primary carbocation in order to torry primaly alkyl bromide primary ally Bronide 2) BNR AV 9 for an 3 Be NMR signals will be there a s NMR signals will be there for e a rs & MR signals will be there

6 from the Bespeerum, there are "s peases" due to produes. & one due to reference sample used, 1) since 8 peaks are there 3-Bromo-pertane it indicate formation - There Be NMR peak 1 - Fire 13NmR peaks 2-Bromo, pentave Br I Conversion of 2, 4 lingshylaz-pentanod to two allyl chlorides a) conversion to secondary allyl chloride. yel, anch OM go Carbocation secondary alty Ichbride

conversion to ternary allyl chloride, ne, anche 2 carbocaties by deide slugt / no sluft 3° carbocants so allyl chloride 13C NMR for secondaryl allyl chloride o b ro There 13 NMR signals are there & for ternary alkyl chloride ofe five 18 C NMR signals leperince b) In given spectrum. Four peaks five peaks are there one due to and other four dove to product 1) This indicates forngarion of