Ammonium Chloride → HCID 86602634, compound

Temperature

-78 °C

Tetrapropylammonium perruthenate (21 mg, 0.06 mmole) was added to a stirred suspension of N-methylmorpholine N-oxide (107 mg, 0.92 mmole), tert-butyl (1R,2R,4R)-2-(tert-butyldimethylsilyloxy)-4-hydroxycyclohexylcarbamate (39B) (210 mg, 0.61 mmole) and crushed 4 A° molecular sieves (500 mg) in dry CH3CN (5 mL). After 5 min, the solvent was removed and the residue was suspended in a 1:1 mixture of EtAc and hexane. This was applied onto a short column of silica gel and eluted with five column volumes of the EtAc/hexane mixture. Removal of the solvents left tert-butyl (1R,2R)-2-(tert-butyldimethylsilyloxy)-4-oxocyclohexylcarbamate (189 mg, 90%). This was dissolved in dry THF and the reaction cooled to −78° C. Lithium tri-sec-butylborohydride (1.1 mL, 1.1 mmole, 1.0 M in THF) was added dropwise and the reaction was left stirring for 1 hr after which it allowed to warm to 0° C. A saturated aq. solution of NH4Cl was carefully added and the reaction was extracted with a mixture of EtOAc/hexane=1/1. The organic extracts were washed with brine and dried (Na2SO4). Removal of the solvents followed by radial chromatography [silica gel, step gradient elution starting with mixture of hexane containing 0 to 30% EtOAc) afforded, in order of elution, the product (127 mg, 67%) as an oil: 1H NMR (CDCl3) 0.05 (s, 3H), 0.07 (s, 3H), 0.86 (m, 9H), 1.42 (s, 9H), 1.47 (m, 1H), 1.57 (m, 2H), 1.70 (m, 3H), 1.91 (m, 1H), 3.43 (s, 1H), 3.83 (m, 1H), 4.05 (d, 1H), 4.48 (d, 1H) and tert-butyl (1R,2R,4R)-2-(tert-butyldimethylsilyloxy)-4-hydroxycyclohexylcarbamate (9 mg, 5%).

1. customthe solvent was removed
2. additionthe residue was suspended in a 1:1 mixture of EtAc and hexane
3. washeluted with five column volumes of the EtAc/hexane mixture
4. customRemoval of the solvents
5. waitleft tert-butyl (1R,2R)-2-(tert-butyldimethylsilyloxy)-4-oxocyclohexylcarbamate (189 mg, 90%)
6. dissolutionThis was dissolved in dry THF
7. waitthe reaction was left
8. temperatureto warm to 0° C
9. extractionthe reaction was extracted with a mixture of EtOAc/hexane=1/1
10. washThe organic extracts were washed with brine
11. dry with materialdried (Na2SO4)
12. customRemoval of the solvents
13. washsilica gel, step gradient elution
14. additionstarting with mixture of hexane containing 0 to 30% EtOAc)
15. customafforded, in order of elution

ORD record

ord-92190f6d8382408b95ab0f145693b512

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07102003B2