Name Interpretation

R-6.2 2,3-Dichloro-6-[4-chloro-2-(hydroxymethyl)-5-oxohex-3-en-1-yl]pyridine-4-carboxylic acid

(I)

(b) The prefixes 'chloro-' and ' [4-chloro-2-(hydroxymethyl)-5-oxohex-3-en-1-yl] ', together with the numerical prefix 'di-' and the locants '2,3', and '6', respectively, indicate the presence of chlorine atoms at positions 2 and 3 and a complex substituent 'R' at position 6; the resulting partial structure is as follows:

(II)

(c) The complex substituent 'R' is analysed in the same way as in (a) and (b), except that the point of attachment (free valence) takes the place of the principal characteristic group. Hence, in the substituent name 4-chloro-2-(hydroxymethyl)-5-oxohex-3-en-1-yl:

(1) the suffix '-yl', together with its locant '1', specifies the attachment of a six-carbon chain, hex, to the parent structure (II); and the subtractive infix 'en', together with its locant, '3', indicates the presence of a double bond between chain atoms 3 and 4, giving the following structure:

(III)

(2) the prefixes 'chloro-', 'hydroxymethyl-', and 'oxo-' together with their respective locants '4', '2', and '5', indicate the presence of a chlorine atom, a hydroxymethyl group, and a doubly-bonded oxygen atom substituting hydrogen atoms at these positions of the parent substituent, giving the structure shown as (IV):

(IV)

Next:

R-6.3 3-(2,3-Dihydroxypropyl)--methylquinoline-2-pentanoic acid
R-6.4 4,4'-Dinitro-2,3'-[ethylenebis(sulfanediyl)]dicyclo-hexane-1-carbaldehyde
R-6.5 1-Methylbutyl 4-(2-acetyl-2-ethylhydrazino)benzoate