(c) The structures of lycopene, beta-carotene and retinol are shown below. Lycopene Beta-carotene H,C CH CH CH OH Retinol (vitamin A) CH3 Using appropriate reaction mechanisms: (i) Show how lycopene is converted into beta-carotene. (ii) Briefly explain how retinol is formed from beta-carotene.

1d

Q2. Consider the nucleophilic substitution reaction between 3-chloro-3-methylpentane and the hydroxide ion: CI x + OH (a) Is the alkyl halide 1°, 2° or 3°? (b) Will the nucleophilic substitution reaction be S₁1 or S№2? (c) Give the substitution mechanism showing all full and partial positive and negative charges, electron movements using curved arrows.

6) 25pts. Draw the structure of the major alkene product (or products) formed by treatment of each of the following haloalkanes with sodium ethoxide in ethanol. Assume the mechanism is E2 elimination. t-BuO K t-BUOH Br CH3 Eto Na F ETOH CH2CH3 CI H- Eto Na -CH2CH3 ELOH H- ČH3 Br Eto Na ELOH CH3 CI, H Eto Na CH2CH3 H3C H D ELOH

Give the major organic product(s) for the following reaction

6, Which one of the following alcohols can not be made by unimolecular nucleophilic substitution (SN,) of an alkyl halide with H2O? benzyl alcohol Ph:COH cydohexanol (CH32CHOH 1-propanol A В C E

How do you convert:(i) Chlorobenzene to biphenyl(ii) Propene to 1-iodopropane(iii) 2-bromobutane to but-2-ene

meta-Chloroperoxybenzoic acid (m-CPBA) is not the only peroxy acid capable of reacting with alkenes to form epoxides. For the reaction below: H3C H3C + CH3CO3H a Draw the structure of the major organic product derived from the alkene.

Organometallic reagents such as sodium acetylide undergo an addition reaction with ketones, giving alcohols: он 1. Na+ -:CCH 2. H30* C-C=CH How might you use this reaction to prepare 2-methyl-1,3-butadiene?

● ● ● ● (A) Cl₂ CH₂=CHCH3 heat Propene OH HOCH₂CHCH₂OH 1,2,3-Propanetriol (glycerol, glycerin) Provide structures for all intermediate compounds (A-D) and describe the type of mechanism by which each is formed. (B) 2A (C₂H₂C1) CI a C (C₂H₂C1O₂) *85 H H₂C=C All hydrogen atoms are implied. Apply formal charges where appropriate. Omit lone pairs and radical electrons from your answer. You do not have to consider stereochemistry. C-Cl H₂ NaOH, H₂O internal displacement Lindlar reduction SN1-substitution SN2-substitution acid-catalyzed hydrolysis addition-elimination allylic halogenation halohydrination vinylic halogenation H H₂C=C Ca(OH)2 D (C3H6O₂) heat → B (C₂H₂O) 00 OU Cl₂, H₂O در H₂O, HCI 2 ster n ? ChemDoodle [Refere ?