(4R)-5,5-dimethyl-4-phenyl-1,3-oxazolidin-2-one

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

Procedure: Reaction of the auxiliary (15) (0.300 g, 1.57 mmol) in solution in tetrahydrofuran (10 ml) at -78° C. with butyllithium (1.5M, 1.06 ml, 1.59 mmol) and cinnamoyl chloride (0.228 ml, 1.73 mmol) for 10 minutes and then at room temperature for 2 hours, with work-up and flash column chromatography using 20% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (26) as a solid (0.503 g, 99%) which was recrystallised from ethyl acetate/40-60 petroleum ether; mp 149° C.; νmax (CDCl3) 1682 and 1771 cm-1 ; [α]D26 (c 1 in CHCl3)=+26.0; (Found: C, 74.79; H, 5.94; N, 4.28. C20H19NO3 requires C, 74.75; H, 5.96; N, 4.36%); δH (CDCl3 ; 200 MHz) 1.04 (3H, s, C(CH3)2), 1.65 (3H, s, C(CH3)2), 5.24 (1H, s, CHPh), 7.20-7.64 (10H, m, ArCH), 7.80 (1H, d, J=15.8, CH=CHPh), 8.07 (1H, d, J=15.8, CH=CHPh); δC (125 MHz; CDCl3) 23.78 (CH3), 28.99 (CH3), 67.24 (CH), 82.47 (C), 117.17 (CH), 126.37 (CH), 128.48 (CH), 128.90 (CH), 130.70 (CH), 134.54 (C), 136.38 (C), 146.53 (CH), 153.33 (CO), 165.04 (CO); m/z (CI+, NH3) 322 (M+ +1)

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

Procedure: Reaction of the auxiliary (15) (0.416 g, 2.19 mmol) in solution in tetrahydrofuran (10 ml) at -78° C. with butyllithium (1.3M, 1.69 ml, 2.20 mmol) and crotonyl chloride (0.229 ml, 2.40 mmol) for 30 minutes and then at room temperature for 2 hours, with work-up and flash column chromatography using 20% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (25) as a solid (0.564 g, 100%) ; mp 104° C.; νmax (CDCl3) 1687 and 1769 cm-1 ; [α]D24 (c 1 in CDCl3)=-82.6; (Found: C, 69.60; H, 6.64; N, 5.35. C15H17NO3 requires C, 69.48; H, 6.61; N, 5.40%); δH (CDCl3 ; 200 MHz) 0.99 (3H, s, C(CH3)2), 1.60 (3H, s, C(CH3)2), 1.93 (3H, d, J=5.4, CH3CHCH), 5.13 (1H, s, CHPh), 7.02-7.40 (7H, m, ArCH and CH3 CH=CH); δC (125 MHz; CDCl3) 18.39 (CH3), 23.60 (CH3), 28.81 (CH3), 67.09 (CH), 82.87 (C), 122.14 (CH), 126.08 (CH), 126.19 (CH), 128.71 (CH), 129.08 (CH), 136.61 (C), 147.31 (CH), 153.50 (CO), 165.07 (CO); m/z (CI+, NH3) 260 (M+ +1).

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

Procedure: Reaction of the auxiliary (15) (0.155 g, 0.81 mmol) in solution in tetrahydrofuran at -78° C. with butyllithium (1.0M, 0.819 ml, 0.821 mmol) and pivaloyl chloride (0.110 ml, 0.89 mmol) for 30 minutes and then at room temperature for 3 hours with work-up and flash column chromatography using 20% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (22) as an oil (0.128 g, 57%); νmax (CHCl3) 1687 and 1775 cm-3 ; [α]D25 (c 0.4 in CHCl3)=-60.3; (Found: C, 69.94; H, 7.84; N, 4.93. C16H21 NO3 requires C, 69.80; H, 7.69; N, 5.09%); δH (CDCl3 ; 300 MHz) 0.98 (3H, s, C(CH3)2), 1.39 (9H, s, C(CH3)3), 1.60 (3H, s, C(CH3)2), 5.11 (1H, s, CHPh), 7.14-7.37 (5H, m, ArCH; δC (125 MHz; CDCl3) 23.66 (CH3), 26.20 (CH3), 28.68 (CH3), 41.63 (C), 69.03 (CH), 81.80 (C), 126.10 (ArCH), 128.44 (ArCH), 128.85 (ArCH), 136.80 (C), 153.50 (CO), 178.00 (CO); m/z (CI+, NH3) 276 (M+ +1).

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

Procedure: Reaction of the auxiliary (15) (0.416 g, 2.19 mmol) in solution in tetrahydrofuran (10 ml) at -78° C. with butyllithium (1.3M, 1.69 ml, 2.20 mmol) and crotonyl chloride (0.229 ml, 2.40 mmol) for 30 minutes and then at room temperature for 2 hours, with work-up and flash column chromatography using 20% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (25) as a solid (0.564 g, 100%) ; mp 104° C.; νmax (CDCl3) 1687 and 1769 cm-1 ; [α]D24 (c 1 in CDCl3)=-82.6; (Found: C, 69.60; H, 6.64; N, 5.35. C15H17NO3 requires C, 69.48; H, 6.61; N, 5.40%); δH (CDCl3 ; 200 MHz) 0.99 (3H, s, C(CH3)2), 1.60 (3H, s, C(CH3)2), 1.93 (3H, d, J=5.4, CH3CHCH), 5.13 (1H, s, CHPh), 7.02-7.40 (7H, m, ArCH and CH3 CH=CH); δC (125 MHz; CDCl3) 18.39 (CH3), 23.60 (CH3), 28.81 (CH3), 67.09 (CH), 82.87 (C), 122.14 (CH), 126.08 (CH), 126.19 (CH), 128.71 (CH), 129.08 (CH), 136.61 (C), 147.31 (CH), 153.50 (CO), 165.07 (CO); m/z (CI+, NH3) 260 (M+ +1).

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

Procedure: Reaction of the auxiliary (15) (0.155 g, 0.81 mmol) in solution in tetrahydrofuran at -78° C. with butyllithium (1.0M, 0.819 ml, 0.821 mmol) and pivaloyl chloride (0.110 ml, 0.89 mmol) for 30 minutes and then at room temperature for 3 hours with work-up and flash column chromatography using 20% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (22) as an oil (0.128 g, 57%); νmax (CHCl3) 1687 and 1775 cm-3 ; [α]D25 (c 0.4 in CHCl3)=-60.3; (Found: C, 69.94; H, 7.84; N, 4.93. C16H21 NO3 requires C, 69.80; H, 7.69; N, 5.09%); δH (CDCl3 ; 300 MHz) 0.98 (3H, s, C(CH3)2), 1.39 (9H, s, C(CH3)3), 1.60 (3H, s, C(CH3)2), 5.11 (1H, s, CHPh), 7.14-7.37 (5H, m, ArCH; δC (125 MHz; CDCl3) 23.66 (CH3), 26.20 (CH3), 28.68 (CH3), 41.63 (C), 69.03 (CH), 81.80 (C), 126.10 (ArCH), 128.44 (ArCH), 128.85 (ArCH), 136.80 (C), 153.50 (CO), 178.00 (CO); m/z (CI+, NH3) 276 (M+ +1).

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

Procedure: To a solution of (13) (1.30 g, 7.89 mmol) in dichloromethane (100 ml) was added carbonyl diimidazole (1.534 g, 9.47 mmol) and the reaction mixture was refluxed for 2 hours. The reaction was quenched with hydrochloric acid (1M) and the product extracted repeatedly with dichloromethane. The combined organic extracts were dried over magnesium sulphate. After concentration in vacuo the residue was purified by flash column chromatography using 40% ethyl acetate/40-60 petroleum ether as eluant to give the title compound (15) (1.24 g, 82%). the reaction mixture was refluxed for 2 hours The reaction was quenched with hydrochloric acid (1M) the product extracted repeatedly with dichloromethane The combined organic extracts were dried over magnesium sulphate After concentration in vacuo the residue was purified by flash column chromatography

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

Procedure: To a solution of (14) (1.655 g, 5.33 mmol) in ethanol (140 ml) was added potassium carbonate (0.369 g. 2.67 mmol) and the solution was refluxed for 30 minutes. After concentration in vacuo, dichloromethane was added and the mixture was washed with saturated aqueous sodium chloride solution. Concentration in vacuo gave crude crystalline solid which was purified by recrystallisation in ethyl acetate/pentane to give the title compound (15) (0.939 g, 92%); mp 149° C.; νmax (CHCl3) 1753 cm-1 ; [α]D25 (c 0.5 in CHCl3)=-77.6; (Found: C, 69.32; H, 7.05; N, 7.38. C11H13NO2 requires C, 69.09; H, 6.85; N, 7.33%); δH (200 MHz; CDCl3) 0.93 (3H, s, C(CH3)2), 1.61 (3H, s, C(CH3)2), 4.66 (1H, s, CHPh), 6.25 (1H, s, NH), 7.25-7.44 (5H, m, ArCH); δC (125 MHz; CDCl3 23.53 (CH3), 28.04 (CH3), 65.93 (CH), 84.63 (C), 126.67 (ArCH), 128.72 (ArCH), 128.93 (ArCH), 137.16 (C), 159.75 (CO) ; m/z (CI+, NH3) 192 (M+ +1). the solution was refluxed for 30 minutes After concentration in vacuo, dichloromethane was added the mixture was washed with saturated aqueous sodium chloride solution Concentration in vacuo gave crude crystalline solid which was purified by recrystallisation in ethyl acetate/pentane