3-methyl-1,4-dioxa-8-azaspiro[4.5]decane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 50 (1.786 g, 7.00 mmol) and 4-piperidone propylene ketal (2.645 g, 16.82 mmol) in toluene (30 mL) was treated with sodium tert-butoxide (1.88 g, 19.56 mmol), (S)-BINAP (44 mg, 0.07 mmol), and tris(dibenzylideneacetone)dipalladium(0) (32 mg, 0.035 mmol) at room temperature. The mixture was heated in an oil bath (80° C., 3 h). The mixture was diluted with ether and brine. The aqueous layer was extracted with two additional portions of ether and the combined organic extracts were washed with brine, dried over Na2SO4, and concentrated under reduced pressure. PCTLC (SiO2, 6 mm, 20% EtOAc-80% hexane) afforded the title compound (51). The aqueous layer was extracted with two additional portions of ether the combined organic extracts were washed with brine dried over Na2SO4 concentrated under reduced pressure

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

Procedure: A mixture of methyl 2-fluorobenzoate (16.0 g, 103.8 mmol) and 4-piperidone propylene ketal (9.8 g, 62.3 mmol) was stirred at room temperature (8 d). Flash chromatography on silica gel (10% MeOH-90% CHCl3) afforded the title compound (44).

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

Procedure: A mixture of methyl 2-fluorobenzoate (16.0 g, 103.8 mmol) and 4-piperidone propylene ketal (9.8 g, 62.3 mmol) was stirred at room temperature (8 d). Flash chromatography on silica gel (10% MeOH-90% CHCl3) afforded the title compound (44).

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

Procedure: A mixture of 2,5-difluorobenzonitrile (2.272 g, 16.33 mmol) and 4-piperidone propylene ketal (2.570 g, 16.34 mmol) was stirred at room temperature (11 d). The resulting mixture was diluted with dichloromethane and sodium carbonate solution and the aqueous layer was extracted with two additional portions of dichloromethane. The combined organic extracts were washed with brine and dried over Na2SO4. The solvent was removed in vacuo. PCTLC (SiO2, 6 mm, 20% EtOAc-80% hexane) afforded the title compound (39). the aqueous layer was extracted with two additional portions of dichloromethane The combined organic extracts were washed with brine dried over Na2SO4 The solvent was removed in vacuo

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

Procedure: A mixture of 4-fluorobenzonitrile (1.22 g, 10.0 mmol) and 4-piperidone propylene ketal (2.02 g, 12.85 mmol) was stirred at room temperature overnight. The resulting mixture was diluted with dichloromethane and sodium carbonate solution and the aqueous layer was extracted with two additional portions of dichloromethane. The combined organic extracts were washed with brine and dried over Na2SO4. The solvent was removed in vacuo. PCTLC (SiO2, 6 mm, 10% EtOH-90% CHCl3) afforded the title compound (34). the aqueous layer was extracted with two additional portions of dichloromethane The combined organic extracts were washed with brine dried over Na2SO4 The solvent was removed in vacuo