Names of some compounds are given. Which one is not correct in IUPAC system?

Question

Names of some compounds are given. Which one is not correct in IUPAC system? (A)  underset3- textmethyl-2- textbutanol mathopCH3- undersetOH mathop underset| mathopCH - undersetCH3 mathop underset| mathopCH -CH3  (B)  underset4- textmethyl-2- textpentyne mathopCH3-CH2≡ C -CH(CH3)2  (C)  underset2- textethyl-3- textmethyl- textbut-1- textene mathopCH3-CH2- undersetCH2 mathop underset|| mathopC - undersetCH3 mathop underset| mathopCH -CH3  (D)  underset3- textmethyl-4- textethyl textheptane mathopCH3-CH2-CH2- undersetCH2CH3 mathop underset| mathopCH- oversetCH3 mathop overset| mathopC H -CH2CH3

Tardigrade Admin · Accepted Answer

CH3- overset6 mathopC H2- overset5 mathopC H2- underset CH2CH3 mathop underset| mathop overset4 mathopC H- oversetCH3 mathop overset3| mathopC H- overset2 mathopC H2- overset1 mathopC H3 Correct IUPAC name is 4-ethyl-3-methyl heptane because substituents are written in alphabatical order.

Q. Names of some compounds are given. Which one is not correct in IUPAC system?

$3 - methyl - 2 - butanol C H_{3} - O H ∣ C H - C H_{3} ∣ C H - C H_{3}$

$4 - methyl - 2 - pentyne C H_{3} - C H_{2} \equiv C - C H (C H_{3})_{2}$

$2 - ethyl - 3 - methyl - but - 1 - ene C H_{3} - C H_{2} - C H_{2} ∣∣ C - C H_{3} ∣ C H - C H_{3}$

$3 - methyl - 4 - ethyl heptane C H_{3} - C H_{2} - C H_{2} - C H_{2} C H_{3} ∣ C H - C ∣ C H_{3} H - C H_{2} C H_{3}$

$C H_{3} - C 6 H_{2} - C 5 H_{2} - C H_{2} C H_{3} ∣ C 4 H - C 3∣ C H_{3} H - C 2 H_{2} - C 1 H_{3}$
Correct IUPAC name is 4-ethyl-3-methyl heptane because substituents are written in alphabatical order.

Q. Names of some compounds are given. Which one is not correct in IUPAC system?

3−methyl−2−butanolCH3​−OH∣CH​​−CH3​∣CH​​−CH3​​

4−methyl−2−pentyneCH3​−CH2​≡C​−CH(CH3​)2​

2−ethyl−3−methyl−but−1−eneCH3​−CH2​−CH2​∣∣C​​−CH3​∣CH​​−CH3​​

3−methyl−4−ethylheptaneCH3​−CH2​−CH2​−CH2​CH3​∣CH−C∣CH3​H​​−CH2​CH3​​

CH3​−C6H2​−C5H2​−CH2​CH3​∣C4​​H−C3∣CH3​H−C2H2​−C1H3​ Correct IUPAC name is 4-ethyl-3-methyl heptane because substituents are written in alphabatical order.

$3 - methyl - 2 - butanol C H_{3} - O H ∣ C H - C H_{3} ∣ C H - C H_{3}$

$4 - methyl - 2 - pentyne C H_{3} - C H_{2} \equiv C - C H (C H_{3})_{2}$

$2 - ethyl - 3 - methyl - but - 1 - ene C H_{3} - C H_{2} - C H_{2} ∣∣ C - C H_{3} ∣ C H - C H_{3}$

$3 - methyl - 4 - ethyl heptane C H_{3} - C H_{2} - C H_{2} - C H_{2} C H_{3} ∣ C H - C ∣ C H_{3} H - C H_{2} C H_{3}$

$C H_{3} - C 6 H_{2} - C 5 H_{2} - C H_{2} C H_{3} ∣ C 4 H - C 3∣ C H_{3} H - C 2 H_{2} - C 1 H_{3}$
Correct IUPAC name is 4-ethyl-3-methyl heptane because substituents are written in alphabatical order.