Identify the correct decreasing order of acidity for the indicated bridgehead protons ( H ) in the following compounds: (i) (ii) (iii)

Step-by-step solution

The acidity of a proton depends on the stability of the conjugate base (carbanion) formed after its removal. In compound (i), the removal of the bridgehead proton forms a carbanion adjacent to three -SO₂- groups. This carbanion is highly stabilized by the strong -I effect of the sulfonyl groups and by p -d delocalization into the empty d-orbitals of sulfur. Crucially, this stabilization does not require the bridgehead carbon to become planar, so it does not violate Bredt's rule. In compound (ii), the removal of the