反应详情

A solution of (R)-1-(4-isopropyl-2-thioxothiazolidin-3-yl)ethanone (11.8 g, 58.1 mmol) in dichloromethane (380 mL) under an atmosphere of nitrogen was cooled to −78° C., titanium tetrachloride (6.37 mL, 58.1 mmol) was added, and the mixture was stirred for 10 min. Diisopropylethylamine (10.12 mL, 58.1 mmol) was added, and the mixture was stirred for 1 h at −78° C. A 1 M solution of hex-5-enal (58.1 mL, 58.1 mmol) in dichloromethane was added, and the mixture was stirred for 2 h at −78° C. The reaction was quenched by addition of half-saturated NH4Cl (30 mL) and warmed to room temperature. The mixture was extracted twice with dichloromethane, and the organic phase was dried and evaporated to provide a residue. Chromatography on silica gel afforded the title compound (12.92 g, 74%). This procedure has also been carried out using the (R)-1-(4-benzyl-2-thioxothiazolidin-3-yl)ethanone auxiliary, with a similar result.

1. stirringthe mixture was stirred for 1 h at −78° C
2. stirringthe mixture was stirred for 2 h at −78° C
3. customThe reaction was quenched by addition of half-saturated NH4Cl (30 mL)
4. extractionThe mixture was extracted twice with dichloromethane
5. customthe organic phase was dried
6. customevaporated
7. customto provide a residue