(3R,7aS)-3-phenyl-3,7a-dihydro-1H-pyrrolo[1,2-c][1,3]oxazol-5-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At RT NaH (oil free, 12.5 mmol) is added to DMSO (15 mL). The mixture is treated portionwise with trimethylsulfoxonium iodide (12.7 mmol) and stirred for 30 min. A solution of (2R,5S)-2-Phenyl-3-oxa-1-azabicyclo[3.3.0]oct-6-en-8-on (4.97 mmol, J. Org. Chem. 1999, 64, 547-555) in DMSO (3.0 mL) is added and the mixture is stirred for 16 h. After cooling to 4° C. water and TBME (100 mL) are added, the layers are separated and the aq. layer is extracted with TBME (100 mL). The combined organic layers are concentrated in vacuo and the residue is purified by FC (heptane/EtOAc 1/1) to give the desired product as a pale yellow oil. LC-MS (basic): tR=0.77 min; [M+H]+=216.3. the mixture is stirred for 16 h are added the layers are separated the aq. layer is extracted with TBME (100 mL) The combined organic layers are concentrated in vacuo the residue is purified by FC (heptane/EtOAc 1/1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At RT NaH (oil free, 12.5 mmol) is added to DMSO (15 mL). The mixture is treated portionwise with trimethylsulfoxonium iodide (12.7 mmol) and stirred for 30 min. A solution of (2R,5S)-2-Phenyl-3-oxa-1-azabicyclo[3.3.0]oct-6-en-8-on (4.97 mmol, J. Org. Chem. 1999, 64, 547-555) in DMSO (3.0 mL) is added and the mixture is stirred for 16 h. After cooling to 4° C. water and TBME (100 mL) are added, the layers are separated and the aq. layer is extracted with TBME (100 mL). The combined organic layers are concentrated in vacuo and the residue is purified by FC (heptane/EtOAc 1/1) to give the desired product as a pale yellow oil. LC-MS (basic): tR=0.77 min; [M+H]+=216.3. the mixture is stirred for 16 h are added the layers are separated the aq. layer is extracted with TBME (100 mL) The combined organic layers are concentrated in vacuo the residue is purified by FC (heptane/EtOAc 1/1)