反应详情

温度

23 °C

Titanium (IV) isopropoxide (0.30 ml, 0.42 g, 1.5 mmol, 11.5 equiv) was added to a stirred solution of 4-[(tert-butyl-dimethyl-silanyloxy)-cyclohexyl-methyl]-7-(2-chloro-ethyl)-6-oxo-1-oxa-5-aza-spiro[2.4]heptane-4-carboxylic acid methyl ester (60 mg, 0.13 mmol, 1.0 equiv) in 2-trimethylsilanyl-ethanol (1.5 ml), and the resultant solution was heated at 100° C. for 17 h. The reaction mixture was allowed to cool to 23° C. and ethyl acetate (30 ml) and water (20 ml) was added. The resultant solution was stirred for 10 min and filtered through Celite. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (15 ml×2). The combined organic layers were dried over sodium sulfate and the solids were filtered. The filtrate was concentrated. The residue was purified by flash column chromatography (10% ethyl acetate-hexanes initially, grading to 20% ethyl acetate-hexanes) to afford 4-[(tert-butyl-dimethyl-silanyloxy)-cyclohexyl-methyl]-7-(2-chloro-ethyl)-6-oxo-1-oxa-5-aza-spiro[2.4]heptane-4-carboxylic acid 2-trimethylsilanyl-ethyl ester (61 mg, 74%) as a colorless oil.

1. filtrationfiltered through Celite
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with ethyl acetate (15 ml×2)
4. dry with materialThe combined organic layers were dried over sodium sulfate
5. filtrationthe solids were filtered
6. concentrationThe filtrate was concentrated
7. customThe residue was purified by flash column chromatography (10% ethyl acetate-hexanes initially