Video narration
Names blur when rings or double bonds shift. Not the name: trace R to what connects first. Allyl: CH2 separates R from the double bond; vinyl attaches to a double-bond carbon. Benzyl: CH2 separates R from the ring; aryl attaches directly. Phenyl is one example of aryl. Isopropyl: central carbon with two methyl branches. -C(CH3)3 is tert-butyl, not neopentyl; neopentyl inserts CH2 before the branching carbon. At R, trace the first connection and ring or double-bond position.