From the following, how many compounds contain at least one secondary alcohol? [figure] Choose the correct answer from the options given below :
- Three
- Two
- Four
- Five
Answer
(1) Three
Solution
A secondary (2°) alcohol has –OH on a carbon bonded to two other carbons.
(I) OH of N–COOH is not an alcoholic OH; the two -CH2OH are 1° no
(II) CH3CH2-CH(OH)-CH2OH: OH on C-2 is 2° yes
(III) both OH are on carbons bonded to three carbons (3°) no
(IV) ring CH(OH) (bonded to two ring carbons) and side-chain CH(OH) are 2° yes
(V) -CH(OH)-CH3 OH is 2° (the other OH is 3°) yes
(VI) two 3° OH and one 1° OH no
(II), (IV) and (V): three compounds.
Answer: (1)