Triethylamine → (7S,9aR)-7-({[(1,1-dimethylethyl)(dimethyl)silyl]oxy}methyl)octahydropyrazino[2,1-c][1,4]oxazine

Participants

Reaction Steps

(7S, 9aR)-octahydropyrazino[2,1-c][1,4]oxazin-7-ylmethanol and (7S, 9aS) -octahydropyrazino[2,1-c][1,4]oxazin-7-ylmethanol (D21) (315 mg,1.83 mmol) was dissolved in 10 mL of anhydrous dichloromethane and treated with Et3N (600 μL, 4.30 mmol) and TDBMSCI (590 mg, 3.91 mmol). The reaction was stirred overnight at room temperature (17 h). It was diluted with dichloromethane (30 mL) and extracted with sat. NaHCO3 (2×20 mL). TLC analysis (EtOAc: MeOH 95:5) showed 2 main products. The organics were dried and the solvent removed leaving an oil, which was purified by flash chromatography (silica, EtOAc→EtOAc:MeOH 90:10). Isolated two products: (7S,9aS)-7-({[(1,1-dimethylethyl)(dimethyl)silyl]oxy}methyl)octahydropyrazino[2,1-c][1,4]oxazine (D22), 253 mg. Direct MS: m/z=287 (M+1).

Provenance & Evidence