Hydroxylamine → (2S,5R)-tert-butyl 5-(allyloxy(tert-butoxycarbonyl)amino)-2-((tert-butyldimethylsilyloxy)methyl)-4-(methoxymethyl)-5,6-dihydropyridine-1(2H)-carboxylate

Temperatur

0 °C

To a stirred solution of tert-butyl allyloxycarbamate (7.39 g, 42.66 mmol) in DMF (150 mL) at rt, potassium 2-methylpropan-2-olate (42.66 mL, 42.66 mmol) was added and gave a purple solution. After 30 min at rt, the mixture was cooled to 0° C. and (2S,5S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-4-(methoxymethyl)-5-(methylsulfonyloxy)-5,6-dihydropyridine-1(2H)-carboxylate (crude, 16.55 g, 35.55 mmol) in 50.0 mL DMF was added. The mixture was then warmed up to rt for 1 h. It was then diluted with ethyl acetate (200 mL) and washed aqueous sat. NaHCO3 solution, brine, dried over MgSO4, filtered and concentrated to give a residue which contains some starting material. The crude was purified on a silica gel column yielding a colorless oil. (19.3 g). 1HNMR shows still a mixture (with hydroxyamine starting material). It was used directly in TBS deprotection.

1. customgave a purple solution
2. temperatureThe mixture was then warmed up to rt for 1 h
3. washwashed aqueous sat. NaHCO3 solution, brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. customto give a residue which
8. customThe crude was purified on a silica gel column
9. customyielding a colorless oil

ORD-Eintrag

ord-bc5afb549ff4447999d02a7b4cd18350

Quelldatensatz

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09309245B2