Problems and exercisesOrganic Structures

These exercises review the whole topic with two molecules. For each question, the page of the corresponding section will help you.

1. Lactic acid

Lactic acid forms in the muscles during intense exercise and gives yogurt its flavour.

1. Write its complete Lewis structure, with all the unshared electron pairs.
2. Which functional groups does it have? Is the alcohol primary, secondary or tertiary?
3. State the hybridization of each carbon atom.
4. Does it have a stereocentre? How many stereoisomers exist and how are they related?
5. Which is the most acidic hydrogen? Write the conjugate base and its resonance forms.
6. Write a functional isomer of lactic acid (formula C₃H₆O₃).

2. Adrenaline

Adrenaline is the hormone that prepares the body to respond to danger.

1. Which functional groups does it have?
2. Point out the stereocentre. Is the molecule chiral?
3. Which is the most basic atom? Write the equilibrium with water.
4. Which are the most acidic hydrogens? Justify your answer by the stability of the conjugate base.
5. Which atom can act as a nucleophile towards an electrophile? Why?

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