1: 90 percent / LDA; THF / hexamethylphosphoric acid triamide / 5 h / -78 - 20 °C 2: 88 percent / lithium aluminium hydride / tetrahydrofuran / Heating View Scheme

1: 90 percent / LDA; THF / hexamethylphosphoric acid triamide / 5 h / -78 - 20 °C 2: 88 percent / lithium aluminium hydride / tetrahydrofuran / Heating 3: 96 percent / pyridine; DMAP / 24 h 4: 70 percent / sodium cyanoborohydride / hexamethylphosphoric acid triamide / 24 h / 130 °C 5: 18 percent / CrO3; glacial CH3COOH / H2O / 5 h View Scheme