tert-Butyl acetate → 1,1-Dimethylethyl 1-(diphenylmethyl)-3-hydroxy-3-azetidineacetate

Temperature

-78 °C

A solution of tert-butyl acetate (566 μL, 4.2 mmol) in THF (10 mL) was cooled to −78° C. To the solution was added LHMDS (5.25 mL of a 1.0 M solution in hexanes, 5.25 mmol), and the resulting mixture was stirred for 20 min at −78° C. To the solution was added 1-(diphenylmethyl)azetidin-3-one (500 mg, 2.1 mmol), prepared using procedures similar to those described in Example 15. After stirring for 1 h, saturated aqueous ammonium chloride was added, and the mixture was warmed to rt. Water and ether were added, and the resulting biphasic mixture was partitioned. The aqueous phase was extracted once with ether. The combined organic extracts were dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by flash chromatography (80% hexanes:20% ethyl acetate) to provide 1,1-dimethylethyl [1-(diphenylmethyl)-3-hydroxyazetidin-3-yl]acetate as a pale yellow solid (644 mg, 1.8 mmol, 87% yield). 1H NMR (400 MHz, CDCl3): δ 7.40 (m, 4H), 7.26 (m, 4H), 7.19 (m, 2H), 4.40 (s, 1H), 4.02 (s, 1H), 3.15 (m, 2H), 3.05 (m, 2H), 2.83 (s, 2H), 1.45 (s, 9H).

1. customprepared
2. stirringAfter stirring for 1 h
3. temperaturethe mixture was warmed to rt
4. customthe resulting biphasic mixture was partitioned
5. extractionThe aqueous phase was extracted once with ether
6. dry with materialThe combined organic extracts were dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe residue was purified by flash chromatography (80% hexanes:20% ethyl acetate)

ORD record

ord-56ed50f5996a401888ac1c71d78a2a5c

Source dataset

uspto-grants-2011_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07999006B2