反应详情

温度

-78 °C

To a solution of intermediate 15.5 (6.82 g, 24.3 mmol) in THF (150 mL) was added dropwise at −780C a solution of n-BuLi in hexanes (18.2 mL, 1.6 M, 29.2 mmol). The mixture was stirred at the same temperature for 40 min, after which of paraformaldehyde (1.82 g, 60.8 mmol) was added in one portion under. After stirring at −78° C. for 10 min., the bath was removed, and the mixture was allowed to warn to RT overnight. Sat. aq. NH4Cl (100 mL) was added, followed by 200 mL of EtOAc. The organic phase was separated and the aq. phase was extracted with 2×100 m T of EtOAc. The combined organic phase was washed with 100 mL of brine, dried (Na2SO4), and concentrated under vacuum. Chromatography (silica gel, 1:15 EtOAc/hexanes) of the crude product afforded the title intermediate (4.15 g, 55%) as colorless oil. Rf 0.3 (1:15 EtOAc/hexanes). 1HNMR (CDCl3) δ 4.29 (s, 2H), 4.24 (s, 1H), 1.95˜2.10 (m, 2H), 1.74˜1.82 (m, 2H), 1.40˜1.70 (m, 4H), 1.20˜1.35 (m, 4H), 0.93 (s, 3H), 0.90 (s, 9H), 0.14 (s, 3H), 0.09 (s, 3H). Intermediate 15.7: 4-{[tert-Butyl(dimethyl)silyl]oxy}-4-(1-butylcyclobutyl)butan-1-ol To a solution of Intermediate 15.6 (2.00 g, 6.44 mmol) in MeOH (100 mL) was added of 10% Pd/C (340 mg, 0.32 mmol). The mixture was subjected to Parr hydrogenation for 2 hr. The reaction mixture was filtered through a celite pad, washed with MeOH, and concentrated in vacuo. The crude product (1.91 g) was used in the next step without further purification. Intermediate 15.8: 4-{[tert-Butyl(dimethyl)silyl]oxy}-4-(1-butylcyclobutyl)butanalde-hyde A solution of oxalyl chloride in dichloromethane (4.6 mL, 2.0 M, 9.2 mmol) cooled at −78° C. was diluted with DCM (12 mL) then a solution of DMSO (1.30 mL, 18.4 mmol) in DCM (5 mL) was added dropwise. The solution was stirred at −78° C. for 30 min then a solution of intermediate 15.7 (1.91 g, 6.07 mmol) in DCM (2 mL) was added dropwise. The temperature was allowed to warm to −40° C. over 30 minutes. To this mixture was added dropwise Et3N (5.1 mL, 36.4 mmol). After the addition was completed, the temperature was allowed to warm to 0° C. over 1 hr. The pH of the mixture was adjusted to −6 using 2N HCl. After extraction with DCM (3×50 mL), the combined organic phase was combined, washed with brine, dried (Na2SO4). Concentration afforded of the crude product, which was subjected to chromatography (silica gel, 1:15 EtOAc/Hexanes). The desired product oil (0.96 g, 48%, 2 steps) was obtained as colorless oil. 1HNMR (CDCl3) δ 9.77 (s, 1), 3.50˜3.55 (m, 1H), 2.40˜2.50 (m, 1H), 2.08˜2.16 (m, 2H), 1.15-1.95 (m, 15H), 0.93 (s, 3H), 0.90 (s, 9H), 0.05 (s, 6H). Intermediate 15.9: Methyl (5Z)-7-{(trans-2,3)-1-[4-{[tert-butyl(dimethyl)silyl]oxy}-4-(1-butylcyclobutyl)butyl]-3-chloropyrrolidin-2-yl}hept-5-enoate To a mixture of intermediate 1.9 (100 mg, 0.407 mmol) and intermediate 15.8 (128 mg, 0.407 mmol) in anhydrous MeOH (5 mL) was added dropwise a solution of NaCNBH3 in THF (0.82 mL, 1.0 M) in THF. After 4 hrs at RT, the reaction mixture was concentrated, and diluted with 15 mL of EtOAc, washed with 10 mL of sat. aq. solution NaHCO3. The aq. phase was extracted with 2×10 mL of EtOAc. Combined organic phase was washed with 10 mL of brine, dried (Na2SO4), concentrated. Flash chromatography over silica gel (eluted with 1:15 EtOAc/Hexanes) afforded 30 mg (14%) of the mixed distereomeric products as a colorless oil. Rf 0.37 (1:9 EtOAc/hexanes). MS (m/z) 542.5 (M+1). Intermediate 15.10 and Intermediate 12.11: Methyl(5Z)-7-{(trans-2,3)-3-chloro-1-[(4S and 4R)-4 hydroxy-4-(1-butylcyclobutyl)butyl]pyrrolidin-2-yl}hept-5-enoate (1st Isomer) To the distereomeric mixtures of intermediate 15.9 (30 mg, 0.06 mmol) was added 2.5 mL of 4.0 M of HCl in dioxane. The reaction mixture was stirred at RT for 2 hr. It was then concentrated, diluted with EtOAc (5 mL), washed with 5 mL of sat. aq. NaHCO3. The aq. phase was extracted with 3×5 mL of EtOAc. The combined organic phase was washed with 5 mL of brine, dried (Na2SO4), concentrated. After chromatography, the 1st diastereoisomer (Intermediate 1.5.10: 4 mg, 16%)4 mg, 16%)) and 4 mg of the second diastereoisomer (Intermediate 15.11: 4 mg, 16%) were isolated both as colorless oil. Intermediate 15.10: 1HNMR (CDCl3) δ 5.40˜5.55 (m, 2H), 3.67 (s, 3H), 3.45 (braod, 1H), 3.25 (broad, 1H), 2.35˜2.30 (m, 21), 2.25˜1.50 (m, 21H), 1.20˜1.45 (m, 8H), 0.90˜0.95 (m, 3H). MS (m/z) 428.3. Intermediate 12.11 1HNMR (CDCl3) δ 5.40˜5.55 (m, 2H), 3.67 (s, 3H), 3.45 (braod, 1H), 3.25 (broad, 1H), 2.35˜2.30 (m, 2H), 2.25˜1.50 (m, 21H), 1.20˜1.45 (m, 8H), 0.90˜0.95 (m, 3H). MS (m/z) 428.3.

1. filtrationThe reaction mixture was filtered through a celite pad
2. washwashed with MeOH
3. concentrationconcentrated in vacuo
4. customThe crude product (1.91 g) was used in the next step without further purification
5. temperatureto warm to −40° C. over 30 minutes
6. additionAfter the addition
7. temperatureto warm to 0° C. over 1 hr
8. extractionAfter extraction with DCM (3×50 mL)
9. washwashed with brine
10. dry with materialdried (Na2SO4)
11. concentrationConcentration
12. customafforded of the crude product, which