C-1 : never break a single bond while drawing a resonance structure.
C-2 : never exceed the octet of a second-period atom (C, N, O).
For the curved-arrow move described below, which statement is correct ?
In CH₃CH=CH-OH a lone pair on oxygen is pushed to make a C=O bond, while the C=C bond is left as it is.

Question

C-1 : never break a single bond while drawing a resonance structure.

C-2 : never exceed the octet of a second-period atom (C, N, O).

For the curved-arrow move described below, which statement is correct ?

structure

In CH₃CH=CH-OH a lone pair on oxygen is pushed to make a C=O bond, while the C=C bond is left as it is.

TestHub · Accepted Answer

The carbon bearing O already has a double bond to carbon, one bond to H and one to O. A new C=O bond gives it five bonds. C-2 is violated.

Chemistry - GOC Question with Solution | TestHub