3,4-dihydro-5H-Benzo[cd]pyren-5-one (prepared)
LiAlH₄ (1 equiv, Alfa Aesar)
THF
Diethyl ether

Under a dinitrogen atmosphere, lithium aluminium hydride (3 mg, 0.08 mmol) in diethyl ether was stirred at 0^oC. The 3,4-dihydro-5H-Benzo[cd]pyren-5-one (20 mg, 0.08 mmol) was dissolved in THF and added to the mixture slowly and the solution left to stir at room temperature for 1 h.

After 1 hour, water and then HCl was added (1:3) sequentially under a dinitrogen atmosphere.
The organics collected and dried with Na₂SO₄ and solvent removed under vacuo, to obtain a crude orange solid.

The crude was columned using (8:2) petroleum ether: ethyl acetate to obtain a pinkish powdered solid (19 mg, 94%).

Particular care should be taken when quenching the reaction due to any unreacted Lithium Aluminium Hydride.

δ_H(500MHz, CDCl₃) ppm: 2.30 - 2.43 (2H, m, HO-CH₂-CH₂), 3.37 (1H, ddd, J 5.0, 7.0, 16.5, HO-CH₂-CH₂), 3.58 (1H, ddd, J 5.0, 8.0, 16.5, HO-CH₂-CH₂), 5.29 (1H, dd, J 3.5, 7.0, HO-CH), 7.83 (1H, d, J 8.0, aryl), 7.96 - 8.17 (7H, m, aryl).           

Selective Reductions. XII. Explorations in Some Representative Applications of Aluminum Hydride for Selective Reductions,
Nung Min Yoon, Herbert C. Brown, JACS., 90.11, 1968.