Restricted rotation (allyl groups) and their effect on 1H-NMR multiplets

Professor Davis gives a short explanation on why the multiplets produced by allyl and vinyl groups can have unusual multiplicities, and how we can use this phenomenon to identify groups with restricted rotation using proton nuclear magnetic resonance.

[@fukpoeslaw3613]

I have a question it's very off topic
I'm thinking of isolating some furanocoumarines from grapefruit juice. but I don't have a clue how to do that besides simply cooking.
could someone tell me please how I can do that best?

[@ChemSurvival]

If you search the literature, you will find Soxhlet extractions and other typical methods of direct extraction from wild celery solids that are reported to be successful IN THE LAB. The problem you are going to run up against in extraction from an aqueous solution ("juice") is finding a safe, low polarity, water immiscible solvent to use. Furanocoumarins are quite hydrophobic, so most researchers seem to turn to hydrocarbons and methylene chloride for these extractions NEITHER OF WHICH I WOULD RECOMMEND YOU USE AT HOME as both are toxic, hydrocarbon solvents are highly flammable, and methylene chloride is a potent carcinogen.