Question

1. List the compounds that have allylic methyl groups. (from the image given)

2. Explain how you could distinguish a compound that contains one or more alkenes from a conpound that contains an aromatic group using NMR.

3. List four ways you could differeniate the compounds shown in the picture using NMR (1H and 13C) and IR.

OH carvone citronellal citronellol geranial {xo! OH geraniol limonene menthone a-terpinene

Answer 1

I have explained for first 4 compounds using different peaks .same is for other compounds for question 3
PAGE NO. DATE: 17 An Allylic carbon is a carbon atom bonded to a carbon atom that in turn is doubly bonded to another carbon ahon The compounds that have allylic methyl groups (from image given are] OK T T a Allylic methyl gf Carvone citronellal citronellolt OH Geranial Geraniol Limonene ß-mycerene y (Arrows indicate Allylic methyl ( مو

I we can distinguish compounds that Contains one or more alkenes from a Compound that contains an aromatic group wsing NMR , as IH and 13e signals' are different for alkenes and Arornatic group C=c- Alkene Aromatic i .H 5.5-6.0 porn 7-8 ppm 100-140ppm 120-160 ppm. 13 с 3) ways to differentiate these compounds. uring NMRC 14 and 13e) and IR o زواره مرد It contains Kehone group, so IR peak at 1720 cm and 13 & NMR for double bonded carbons at 100-140 ppm. andin H NMR foss, we will get 7 signals and in 13C NMR 10 signals

PAGE NO. DATE: n citronellal IR peak for Aldehydic Hydrogen (we get a shoulder bands) at 272042820 cm and IR peak for c= c at 1600-1680 'H NMR for Aldehydie proton at 9.5-10 ppm & IR peak for aldehydic carbon at . 1725 cm-l, - - IR' for Aromatics at 1500-1600 cm W 'H NMR for Aromatic Hydrogens at 7.5 ppm & total s signal p-cymene 13C NMR for Aromatic carbons ! at 110-180 blom on IR and for OH at 3600 cmt e=c at 1600-1680 cm) * citronellol . Like these , we can these compounds using and 13C NMR differentiale IR HNMR all