Tetrahydrofuran → Ethyl (2E)-5-(tert-butoxycarbonylamino)5-methylhex-2-enoate

Triethylphosphonoacetate (1.96 ml, 9.8 mmol) was dissolved in THF (30 ml). Potassium tert-butoxide (1.10 g, 9.8 mmol) was added. The solution was stirred for 40 min at room temp. A solution of 3-(tert-butoxycarbonylamino)-3-methylbutanal (1.10 g, 5.5 mmol) in THF (6 ml) was added slowly. The solution was stirred at room temp. for 75 min. It was diluted with ethyl acetate (100 ml) and 1N hydrochloric acid (100 ml). The aqueous phase was extracted with ethyl acetate (2×50 ml). The combined organic layers were washed with a saturated solution of sodium hydrogencarbonate (60 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by column chromatography on silica (90 g) with ethyl acetate/heptane (1:4) to give 1.27 g of ethyl (2E)-5-(tert-butoxycarbonylamino)-5-methylhex-2-enoate.

1. stirringThe solution was stirred at room temp. for 75 min
2. extractionThe aqueous phase was extracted with ethyl acetate (2×50 ml)
3. washThe combined organic layers were washed with a saturated solution of sodium hydrogencarbonate (60 ml)
4. dry with materialdried over magnesium sulfate
5. customThe solvent was removed in vacuo
6. customThe crude product was purified by column chromatography on silica (90 g) with ethyl acetate/heptane (1:4)

ORD record

ord-7885fedbc7674e22a0ce7bcfbf1286f2

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350767B1