2,2-dimethyl-1,1-di(propan-2-yloxy)pentan-3-one

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

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

Procedure: To a solution of keto aldehyde 19 (6.40 g, 50 mmol) in isopropanol (100 mL) was added triisopropyl orthoformate (16.7 mL, 75 mmol) and p-TsOH (951 mg, 5.0 mmol). After the mixture was stirred for 3 h, it was poured into brine (100 mL) and extracted with ether (3×100 mL). The combined organic layers were dried and concentrated in vacuo to give 50 as a pale yellow liquid (10.12 g, 88%: IR (neat) 2976, 2935, 1697, 1460, 1379, 1314, 1174, 1125, 1082, 1028 cm−1; 1H NMR (300 MHz, CDCl3) δ 4.58 (s, 1H), 3.80 (sept, J=6.1 Hz, 2H), 2.51 (q, J=7.2 Hz, 2H), 1.18 (d, J=6.2 Hz, 6H), 1.12 (s, 6H), 1.08 (d, J=6.2 Hz, 6H), 0.95 (t, J=7.2 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 215.8, 104.0, 70.7, 53.4, 32.8, 23.8, 22.4, 20.3, 8.0; HRMS calcd for C10H19O2 (M-C3H7) 171.1385, found 171.1377. extracted with ether (3×100 mL) The combined organic layers were dried concentrated in vacuo

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2,-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2,-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2,-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2,-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2,-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products

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

Procedure: To a solution of keto aldehyde 19 (6.40 g, 50 mmol) in isopropanol (100 mL) was added triisopropyl orthoformate (16.7 mL, 75 mmol) and p-TsOH (951 mg, 5.0 mmol). After the mixture was stirred for 3 h, it was poured into brine (100 mL) and extracted with ether (3×100 mL). The combined organic layers were dried and concentrated in vacuo to give 50 as a pale yellow liquid (10.12 g, 88%: IR (neat) 2976, 2935, 1697, 1460, 1379, 1314, 1174, 1125, 1082, 1028 cm−1; 1H NMR (300 MHz, CDCl3) δ 4.58 (s, 1H), 3.80 (sept, J=6.1 Hz, 2H), 2.51 (q, J=7.2 Hz, 2H), 1.18 (d, J=6.2 Hz, 6H), 1.12 (s, 6H), 1.08 (d, J=6.2 Hz, 6H), 0.95 (t, J=7.2 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 215.8, 104.0, 70.7, 53.4, 32.8, 23.8, 22.4, 20.3, 8.0; HRMS calcd for C10H19O2 (M-C3H7) 171.1385, found 171.1377. extracted with ether (3×100 mL) The combined organic layers were dried concentrated in vacuo

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1,1-diisopropoxy-2,2-dimethyl-3-pentanone (3.29 g) in 15 mL of THF is added slowly to a solution of lithium diisopropylamide (15.7 mmol) in 20 mL of THF cooled to −78° C., the mixture is stirred for 30 minutes, warmed to −40° C. and stirred for 30 minutes, then recooled to −78° C. A solution of (2S)-2-methyl-4-pentenal (16.36 mmol) in 2 mL of CH2Cl2 is added and the mixture is stirred for 1 hour at −78° C. Saturated aq. NH4Cl is added and the mixture is warmed to ambient temperature and extracted with ethyl acetate. The extract is dried over Na2SO4, filtered, and evaporated. The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products. warmed to −40° C. stirred for 30 minutes recooled to −78° C the mixture is stirred for 1 hour at −78° C the mixture is warmed to ambient temperature extracted with ethyl acetate The extract is dried over Na2SO4 filtered evaporated The residue is purified by silica gel chromatography (2% ethyl acetate/hexanes) to separate the two diastereomeric products