Nomenclature OF Organic Compounds flash cards

1. 1.What are the three essential parts of an IUPAC name, in order?

   Prefix + Word Root + Suffix. Word root = number of carbons in the parent chain; prefix = substituents; suffix = principal functional group (and degree of saturation).

   Hint: Think substituent, backbone, functional group.

2. 2.Give the word roots for chains of 1 to 10 carbons.

   1 Meth, 2 Eth, 3 Prop, 4 But, 5 Pent, 6 Hex, 7 Hept, 8 Oct, 9 Non, 10 Dec.

   Hint: First four are historical; from 5 onward they are Greek/Latin numbers.

3. 3.What does the primary suffix denote, and give it for single, double and triple bonds?

   Degree of saturation. Single bond $\rightarrow$ -ane; C=C double bond $\rightarrow$ -ene; C$\equiv$C triple bond $\rightarrow$ -yne.

   Hint: ane/ene/yne.

4. 4.What does the secondary suffix denote?

   The principal (characteristic) functional group, e.g. -ol (alcohol), -al (aldehyde), -one (ketone), -oic acid, -amine.

   Hint: Added after the primary suffix.

5. 5.When adding a suffix beginning with a consonant (like -nitrile, -diene), is the terminal 'e' of the alkane retained?

   Yes. Terminal 'e' is dropped only before a suffix starting with a vowel (a,e,i,o,u,y). Before a consonant it is retained: e.g. propane $\rightarrow$ propanenitrile.

   Hint: but-2-ene-1,4-diol keeps 'e' before the 'd'.

6. 6.Rule 1 for choosing the parent chain: what governs the selection?

   Select the longest continuous carbon chain that contains the principal functional group and the maximum number of multiple bonds.

   Hint: Longest chain including the key group.

7. 7.Two chains of equal length compete for parent selection. What is the tie-breaker?

   Choose the chain with the greater number of substituents (side chains).

   Hint: More branch points wins.

8. 8.For an alkane with a chain drawn bent, how do you find the longest chain?

   Count carbons along every possible path, not just the horizontal one; the longest may go around a corner. The longest chain need not be the one written straight across.

   Hint: Trace all zig-zag paths.

9. 9.State the lowest-locant rule (rule of first point of difference).

   Number the chain so the principal characteristic group / multiple bonds / substituents get the lowest set of locants; compare locant sets term by term at the first point of difference.

   Hint: $\{2,6,7\}$ beats $\{3,4,8\}$ at first difference.

10. 10.What is the priority order for assigning lowest locants when groups compete?

    1) Principal characteristic group (suffix) $\rightarrow$ 2) skeletal features / multiple bonds (ene, yne) $\rightarrow$ 3) prefixes/substituents as a set $\rightarrow$ 4) alphabetically first substituent.

    Hint: Functional group beats double bond beats substituents.

11. 11.How are substituent prefixes ordered in the final name?

    Alphabetically, ignoring multiplying prefixes (di, tri, tetra) but counting iso, neo, cyclo. e.g. ethyl before methyl; but consider 'e' of ethyl vs 'm' of methyl.

    Hint: Alphabetize the substituent root, not the multiplier.

12. 12.Do 'di/tri/tetra' count for alphabetizing? What about 'iso'?

    di/tri/tetra/bis etc. are ignored in alphabetizing. But 'iso' and 'neo' are part of the name and are counted (isopropyl alphabetized under 'i').

    Hint: Multiplying = ignore; iso/neo = count.

13. 13.When two locant sets are equal, how do you decide numbering direction?

    Give the lowest locant to the substituent that comes first alphabetically.

    Hint: Alphabet breaks the tie.

14. 14.Name the substituent groups: $-CH_3$, $-C_2H_5$, $-CH(CH_3)_2$.

    $-CH_3$ = methyl; $-C_2H_5$ = ethyl; $-CH(CH_3)_2$ = isopropyl (1-methylethyl) or propan-2-yl.

    Hint: Remove one H from the alkane, change -ane to -yl.

15. 15.Draw/identify: n-propyl vs isopropyl.

    n-propyl $= -CH_2CH_2CH_3$ (attached at end carbon); isopropyl $= -CH(CH_3)_2$ (attached at middle carbon).

    Hint: Point of attachment differs.

16. 16.Name the four $C_4H_9-$ groups.

    n-butyl $-CH_2CH_2CH_2CH_3$; sec-butyl $-CH(CH_3)CH_2CH_3$; isobutyl $-CH_2CH(CH_3)_2$; tert-butyl $-C(CH_3)_3$.

    Hint: n, sec, iso, tert.

17. 17.What is the structure and preferred name of the neopentyl group?

    Neopentyl $= -CH_2C(CH_3)_3$, i.e. 2,2-dimethylpropyl.

    Hint: Quaternary carbon next to the $CH_2$.

18. 18.How is a complex (branched) substituent named and alphabetized?

    Named in parentheses with its own internal numbering (attachment carbon = 1), and alphabetized by the first letter of its complete name. e.g. (1,2-dimethylpropyl) alphabetized under 'd'.

    Hint: First letter of the full complex name counts, including 'dimethyl'.

19. 19.List the seniority of common functional groups for choosing the PRINCIPAL characteristic group (highest first).

    Carboxylic acid > sulfonic acid > ester > acid halide > amide > nitrile > aldehyde > ketone > alcohol > amine > ether. (Cations/carboxylic acids sit near the top.)

    Hint: COOH is king; ether is never a suffix.

20. 20.Which functional groups can ONLY be expressed as prefixes (never as principal suffix)?

    Halogens ($-F,-Cl,-Br,-I$ = fluoro/chloro/bromo/iodo), $-NO_2$ (nitro), $-OR$ (alkoxy), $-N=O$ (nitroso), $-N_3$ (azido).

    Hint: Halo, nitro, alkoxy are always prefixes.

21. 21.How is the principal functional group treated versus lower-priority groups also present?

    Highest-priority group $\rightarrow$ expressed as suffix; all lower-priority groups $\rightarrow$ expressed as prefixes.

    Hint: One suffix, rest become prefixes.

22. 22.Give the suffix and prefix used for the $-COOH$ group.

    Suffix: -oic acid (or -carboxylic acid if $C$ not in chain); Prefix: carboxy.

    Hint: Ethanoic acid; 3-carboxy... when subordinate.

23. 23.Give the suffix and prefix for $-CHO$ (aldehyde).

    Suffix: -al (carbon counted in chain) or -carbaldehyde (carbon not in chain); Prefix: oxo (=O) or formyl ($-CHO$).

    Hint: Ethanal; cyclohexanecarbaldehyde.

24. 24.Give the suffix and prefix for $>C=O$ (ketone).

    Suffix: -one; Prefix: oxo.

    Hint: Propan-2-one; 3-oxobutanoic acid.

25. 25.Give the suffix and prefix for $-OH$ (alcohol).

    Suffix: -ol; Prefix: hydroxy.

    Hint: Ethanol; 2-hydroxypropanoic acid (lactic acid).

26. 26.Give the suffix and prefix for $-NH_2$ (amine).

    Suffix: -amine; Prefix: amino.

    Hint: Ethanamine; 2-aminoethanol.

27. 27.Give the suffix and prefix for $-C\equiv N$ (nitrile).

    Suffix: -nitrile (C counted) or -carbonitrile (C not counted); Prefix: cyano.

    Hint: Propanenitrile has 3 C total.

28. 28.Give the suffix and prefix for the ester group $-COOR$.

    Suffix/name: alkyl ...oate (e.g. methyl ethanoate); Prefix: (alkoxycarbonyl) or acyloxy.

    Hint: Acid part named as ...oate, alcohol part as alkyl.

29. 29.Give the suffix and prefix for $-CONH_2$ (amide).

    Suffix: -amide (or -carboxamide); Prefix: carbamoyl.

    Hint: Ethanamide; C in chain.

30. 30.How are ethers ($R-O-R'$) named in IUPAC substitutive nomenclature?

    The smaller $-OR$ group is a substituent named alkoxy on the larger (parent) chain. e.g. $CH_3OCH_2CH_3$ = methoxyethane.

    Hint: Longer chain = parent; $-OR$ = prefix.

Open the interactive deck for the other 74 cards, with self-grading so the ones you keep missing come back.