Question

An unknown compound with molecular formula C8H8O2 is below. Provide a structure consistent and explain the reasoning.

Answer 1

Answer :

· Molecular formula of the compound, Cq Hg Og To determin the structure of this molecule we need to determine the double bound equivalent of the compound. Formula of determining double bond equi valam! (DBE) is DBE = {c+5) - - where, er Number of carbon atom. = 8 H+ :n H-atom -8 xa Number of halogen atom 20 ♡ → number of N-acum 20".. -070 6. DBE = 18+1)- = 9-4. As double bund' equivalent (DBE) >4 50, in the structure of the compound there must be an aromatic ging.

The aromatic benzene ping contain 6-earbon atom. But the compound cq Hold has 8- carbon atom . so there must be a substituent in the coromatic ging. So - #. #. Substituent. (4-D BE system) Bz ring is considered as 4-DBE system due to the resonance 5-DBE bo, the substituent contains toro d one double bond with two orafim two coatom and three tatom So, the substituent may be an acid group or an ester group, as thrie is one double bond and two 0-atom.

5o the probabie structures is a e-O-H # OL -0-Cha [Ester] HH there is So, two posible structure for the Cghg and these two : Strue fure can be defferentiale or identified by IR- streching, band of carbonyi (co) group. HI -CH₂-C-0-H . It give co-streching frequency in the range of . 1710 1730 cm nzylic acid H OLĈ -0-cltg.gives eo- streching frequency in the Methejl benguet. range 1795 - 1760 cm".

(Answered)