Can you synthesize phenol from salicyladehyde?
It is possible to convert salicylaldehyde into phenol in a two-step process. Firstly, salicylaldehyde is oxidized to salicylic acid with a standard reagent like $\ce{KMnO4}$ (see the answers to this question).

In the second step, salicylic acid is thermally decarboxylated to phenol in a simple distillation apparatus. Solid salicylic acid is strongly heated in a round-bottom flask equipped with a short path distillation head with thermometer. Heating is maintained to keep a reasonable distillation rate of the desired product (phenol passes over at a temperature range from 145 to 165 °C). Most by-products of the reaction, like phenyl salicylate, have higher boiling points and remain in the residue. The crude product can finally be purified by vacuum distillation, for example, at a pressure of 30 Torr and a temperature range of 85 - 90 °C (reference).