Shown below is the structure of methyl acetate with three different α, β and γ carbon-oxygen bonds.
(see structure)
The correct order of bond length of these bonds is :
(A)α > β > γ
(B)α < β < γ✓ Correct
(C)α = β = γ
(D)α < β = γ
Answer: (B)
Solution
In methyl acetate the carbonyl bond α is a genuine double bond and is the shortest. Delocalisation of a lone pair of the ester oxygen into the carbonyl gives the C−O bond β partial double-bond character, so it is shorter than an ordinary single bond but longer than the double bond α. The O−CH3 bond γ is an ordinary single bond untouched by this delocalisation and is the longest. The order of increasing bond length is α<β<γ.
JEE Main · 2026 · 06 Apr 2026 · Shift 2 · Single correct option
