Why it is not possible to have a straight chain trialdehyde?

Answer 1

A straight-chain trialdehyde is not possible due to the structural requirements of aldehydes, which contain a carbonyl group (C=O) bonded to a terminal carbon atom. In a trialdehyde, three aldehyde groups would require three terminal carbons, but this would lead to a carbon chain that cannot satisfy the tetravalency of carbon. Specifically, if one tries to extend the chain to accommodate three aldehyde groups at both ends, it would result in structural instability or violate the tetravalency of carbon. Thus, trialdehydes must have branched or cyclic structures instead.