Fumaric acid may be converted into oxaloacetic acid by a two-stage route that passes through the intermediate Q. $\text{HO}_2\text{CCH=CHCO}_2\text{H} \xrightarrow{\text{step 1}} Q \xrightarrow{\text{step 2}} \text{HO}_2\text{CCOCH}_2\text{CO}_2\text{H}$ In the laboratory, either of these stages can be carried out with a single reagent. What might the intermediate Q be, and which reagent could be used for step 2?
- A$\text{HO}_2\text{CCHBrCH}_2\text{CO}_2\text{H}$ ; warm acidified $\text{KMnO}_4$
- B$\text{HO}_2\text{CCHBrCH(OH)CO}_2\text{H}$ ; warm $\text{NaOH(aq)}$
- C$\text{HO}_2\text{CCH(OH)CH}_2\text{CO}_2\text{H}$ ; Fehling’s solution
- D$\text{HO}_2\text{CCH(OH)CH}_2\text{CO}_2\text{H}$ ; warm acidified $\text{K}_2\text{Cr}_2\text{O}_7$