反应详情

A flame dried 250-mL, round-bottom flask was charged with sodium hydride (2.4 g, 60.0 mmol) and trimethyloxosulfonium iodide (13.2 g, 60 mmol). The flask was evacuated and refilled with N2, and dry DMSO (100 mL) was added. The mixture was stirred at rt for 1 h to afford a solution. A second 500-mL, round-bottom flask was charged with tert-butyl (2S,4S)-4-(benzyloxymethyl)-5-methyl-1-oxohexan-2-ylcarbamate (14 g, 40 mmol) and THF (150 mL). The flask was evacuated and refilled with N2, and the sulfur ylid solution prepared above was added through a cannula. The resulting mixture was stirred for 1 h at rt. The reaction mixture was quenched with brine and extracted with EtOAc (3×200 mL). The combined organic phases were dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel to afford tert-butyl (1S,3S)-3-(benzyloxymethyl)-4-methyl-1-((R)-oxiran-2-yl)pentylcarbamate (7.2 g, 50%). 1H NMR (400 MHz, CD3OD): δ 8.00 (s, 1H), 7.74 (d, J=8.4 Hz, 1H), 7.55 (m, 1H), 7.17 (m, 1H), 4.50 (m, 2H), 3.84-3.68 (m, 2H), 3.45 (m, 1H), 3.27 (s, 3H), 3.25-3.18 (m, 3H), 2.13 (m, 2H), 1.89-1.72 (m, 2H), 1.55 (m, 3H), 1.32-1.11 (m, 9H), 0.99-0.80 (m, 12H); MS: 364 (M++1)

1. customA flame dried 250-mL, round-bottom flask
2. customThe flask was evacuated
3. additionrefilled with N2, and dry DMSO (100 mL)
4. additionwas added
5. customto afford a solution
6. customThe flask was evacuated
7. additionrefilled with N2
8. customthe sulfur ylid solution prepared
9. additionabove was added through a cannula
10. stirringThe resulting mixture was stirred for 1 h at rt
11. customThe reaction mixture was quenched with brine
12. extractionextracted with EtOAc (3×200 mL)
13. dry with materialThe combined organic phases were dried over Na2SO4
14. filtrationfiltered
15. concentrationconcentrated in vacuo
16. customThe residue was purified by column chromatography on silica gel