Reaktion #155471

Reaktionsgleichung

1,4-dioxaspiro[4.5]decan-8-one

methyl 2-(benzyloxycarbonylamino)-2-(dimethoxyphosphoryl)acetate

1,1,3,3-tetramethylguanidine

→

methyl 2-(benzyloxycarbonylamino)-2-(1,4-dioxaspiro[4.5]decan-8-ylidene)acetate

Ausbeute 26.8%

Lösungsmittel

EtOAc

EtOAc

EtOAc

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe organic layer was washed with 1N HCl (75 mL), H2O (100 mL) and brine (100 mL)
2. 2
   Trocknendried (MgSO4)
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe residue was purified via Biotage (5% to 25% EtOAc/Hexanes; 300 g column)
6. 6
   workup.ADDITIONThe combined fractions containing the product
7. 7
   Einengenwere then concentrated under vacuum
8. 8
   Sonstigethe residue was re-crystallized from hexanes/EtOAc

Vorschrift

A solution of 1,4-dioxaspiro[4.5]decan-8-one (15 g, 96 mmol) in EtOAc (150 mL) was added to a solution of methyl 2-(benzyloxycarbonylamino)-2-(dimethoxyphosphoryl)acetate (21.21 g, 64.0 mmol) in 1,1,3,3-tetramethylguanidine (10.45 mL, 83 mmol) and EtOAc (150 mL). The resulting solution was the stirred at ambient temperature for 72 h and then it was diluted with EtOAc (25 mL). The organic layer was washed with 1N HCl (75 mL), H2O (100 mL) and brine (100 mL), dried (MgSO4), filtered and concentrated. The residue was purified via Biotage (5% to 25% EtOAc/Hexanes; 300 g column). The combined fractions containing the product were then concentrated under vacuum and the residue was re-crystallized from hexanes/EtOAc to give white crystals that corresponded to methyl 2-(benzyloxycarbonylamino)-2-(1,4-dioxaspiro[4.5]decan-8-ylidene)acetate (6.2 g) 1H NMR (400 MHz, CDCl3-d) δ ppm 7.30-7.44 (5H, m), 6.02 (1H, br. s.), 5.15 (2H, s), 3.97 (4H, s), 3.76 (3H, br. s.), 2.84-2.92 (2H, m), 2.47 (2H, t, J=6.40 Hz), 1.74-1.83 (4H, m). LC (Cond. OL1): Rt=2.89 min. LC/MS: Anal. Calcd. For [M+Na]+ C19H23NNaO6: 745.21. found: 745.47.

Quelle