EM120 - RGANI EMISTRY WRK SEET 1 1. Answer the following questions with respect to compounds (A) and (B): (B) (A) 5 2 ( 3 ) 2 6 3 2 2 2 ( 3 ) 3 1 2 4 3 () 2 2 3 3 1 3 2 3 (a) Draw the bond-line notation for the compounds. (a) isopropyl tert-butyl Alkyne Ester Alkene Ether sec-butyl (b) Ketone Alcohol Alkene (b) Identify the following substituents on structure 1(A): (i) an isopropyl group (ii) a tert-butyl group (iii) a sec-butyl group (c) Identify all the functional groups in compounds (A) and (B).
(d) Identify the hybridization of the numbered atoms in structures (A) and (B). ompound A Atom 1() = sp 3 ; atom 2 () = sp; atom 3() sp 3; atom 4 () = sp 2, Atom 5() = sp 3 atom 6 () = sp 2 ompound B Atom 1() = sp 3, atom, 2() sp 2, atom 3() = sp 2 2. Name the compounds (a) to (d) below according to the IUPA rules. (a) 3 2 ( 3 ) 2 ( 2 3 ) 3 (b) 3,5-dimethylheptane 3-ethyl-2-methylheptane (c) (d) 4-ethyl-2-methylheptane 2-methyl-4-propylheptane
3. Write (i) structural formulae and (ii) draw the bond line notation for the following compounds: (a) 2,2,4-trimethylhexane 3 3 2 3 2 3 3 (b) 3-ethyl-2,4,5-trimethyloctane 3 3 3 2 3 2 3 2 3 (c) 2-bromo-2,4,6-trimethyloctane 3 2 3 3 3 3 4 (a) Explain why 2-sec-butyloctane is an incorrect IUPA name. The parent compound is incorrect it should be a decane (longest chain has 10 arbons)
(b) (i) Write a correct IUPA name and (ii) draw the bond-line notation for the intended compound. The correct name is 3,4-dimethyldecane 3,4-dimethyldecane (c) Identify a primary, secondary, tertiary and a quaternary carbon atom in 3 ( 3 ) 2 2 ( 3 ) 3. 3 3 1 0 3 3 4 0 3 0 3 2 0
EM 120: RGANI EMISTRY: WRKSEET 2 1. Name the following compounds using the IUPA system. If any alcohols are present, indicate whether they are primary, secondary or tertiary. ANSWER: (a) 3-hexene (b) 2-octyne (c) 2-methyl-1-butanol (primary alcohol) (d) 3-methyl-2-pentanol (secondary alcohol) (e) 2-methyl-2-butanol (tertiary alcohol) (f) 2,2-dimethyl-3-hexanone (g) 7,8-dimethylnonanal (h) 6-chloro-2,3-dimethylnonanoic acid
2. Draw structures for: (a) 4-isopropyldecane (b) 2,2-dichloropropane (c) 3-heptyne (d) 5,5-dimethylnonane (e) 2-butanol (f) 2-methyl-2-propanol (g) 3-methylpentanal (h) 3-hydroxy-2-hexanone (i) octanoic acid (j) 4-bromo-5 hydroxynonanoic acid
3. There are four structural isomers with the molecular formula 4 9. Draw structures for the four isomers. ne of these can exist as a pair of optical isomers which one is this? 4. The substance 2-butanol displays optical isomers. Indicate the chiral carbon with a. Draw three dimensional representations of the two enantiomers and label the isomers clearly. 2 3 3 2 3 (S)-2-butanol 3 (R)-2-butanol 5. Draw structures for the cis- and trans-isomers of 1-chloro-1-propene.
6. Determine the configuration of each of the following alkenes: (Z)-isomer (E)-isomer (E)- isomer (Z)- isomer 7. Draw the structure of trans-1,3-dichlorocyclobutane. l l or l l 8. Explain why the cyclohexane boat conformation is much less stable than the chair conformation. The arrangement of hydrogens on carbons- 2 and 3 are too close causing steric strain which is not experience in the chair conformation. 2 3
9. a) Find the stereogenic center (chiral centre, ) in i) 3 2 I 2 3 ii) F 3 I 2 3 2 3 No chiral centre F 3 3 F iii) 3-methylcyclohexene iv) 2,3-dibromobutane 10. a) Which of the following compounds is chiral? i) 1-bromo-1-phenylethane ii) 1-bromo-2-phenylethane b) Draw three-dimensional structures (perspective formulae) for the two enantiomers of the chiral compound in problem 10(a). hiral 3 (S)-1-bromo-1-phenylethane 3 (R)-1-bromo-1-phenylethane
11. The figure below shows Fischer projection structures of 2,3-dichlorobutane. lassify the following molecules of as either enantiomers, chiral, achiral or meso forms. Locate the planes of symmetry, if any, and assign the corresponding configurations (R) or (S). l 3 S l S l 3 R R l 3 S R l l l l 3 R S Plane of symmetry 3 3 3 3 enantiomers, chiral identical, achiral a meso form