Which of the following resonating structure of 1-methoxy-1, 3-butadiene is least stable?

Question

Which of the following resonating structure of 1-methoxy-1, 3-butadiene is least stable? (A)  overset-CH2-CH= CH-CH = overset+O-CH3 (B) CH2= CH2-CH2-CH= overset+O-CH3 (C)  overset-CH2- overset+CH-CH = CH -O-CH3 (D) CH2=CH - overset-CH - overset+CH -O-CH3

Tardigrade Admin · Accepted Answer

(a) The molecule in which all the atoms have completed octet is more stable than atom which have incomplete octet (b) More number of resonating structures, more will be the stability (a) and (b) have complete octet but in (c) and (d) all atoms do not have complete octet. Hence (c) and (d) are unstable <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/chemistry/8cf126d182d88cc04b71f6255a893f08-.png" />

Q. Which of the following resonating structure of 1-methoxy-1, 3-butadiene is least stable?

$C - H_{2} - C H = C H - C H = O + - C H_{3}$

$C H_{2} = C H_{2} - C H_{2} - C H = O + - C H_{3}$

$C - H_{2} - C + H - C H = C H - O - C H_{3}$

$C H_{2} = C H - C - H - C + H - O - C H_{3}$

Q. Which of the following resonating structure of 1-methoxy-1, 3-butadiene is least stable?

C−H2​−CH=CH−CH=O+−CH3​

CH2​=CH2​−CH2​−CH=O+−CH3​

C−H2​−C+H−CH=CH−O−CH3​

CH2​=CH−C−H−C+H−O−CH3​

$C - H_{2} - C H = C H - C H = O + - C H_{3}$

$C H_{2} = C H_{2} - C H_{2} - C H = O + - C H_{3}$

$C - H_{2} - C + H - C H = C H - O - C H_{3}$

$C H_{2} = C H - C - H - C + H - O - C H_{3}$