Réaction #155471

Équation de réaction

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

Rendement 26.8%

Solvants

EtOAc

EtOAc

EtOAc

Conditions de réaction

Traitement

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

Mode opératoire

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.

Source