Chlorotrimethylsilane → (+)-Pinanediol 3-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)phenylboronate

HRID 2077111노트

반응식

HRID 2077111 반응식
[Li]CCCC.Br[C:7]1[CH:8]=[C:9]([C:13]2[O:14][CH2:15][C:16]([CH3:19])([CH3:18])[N:17]=2)[CH:10]=[CH:11][CH:12]=1.C[O:21][B:22](OC)[O:23]C.C[Si](Cl)(C)C.[C:32]12([OH:43])[CH2:40][CH:36]([C:37]1([CH3:39])[CH3:38])[CH2:35][CH2:34][C:33]2([OH:42])[CH3:41]>CCCCCC.C1COCC1.CCOCC>[C:32]12([OH:43])[CH2:40][CH:36]([C:37]1([CH3:39])[CH3:38])[CH2:35][CH2:34][C:33]2([OH:42])[CH3:41].[CH3:18][C:16]1([CH3:19])[CH2:15][O:14][C:13]([C:9]2[CH:8]=[C:7]([B:22]([O-:23])[O-:21])[CH:12]=[CH:11][CH:10]=2)=[N:17]1

참가 물질

9

반응물 5

HCID 6397ChlorotrimethylsilaneHCID 8470Trimethyl borateHCID 128530432-(3-Bromophenyl)-4,5-dihydro-4,4-dimethyloxazoleHCID 219250472,6,6-Trimethylbicyclo[3.1.1]heptane-1,2-diolHCID 178418339Butyllithium

생성물 1

HCID 131726603(+)-Pinanediol 3-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)phenylboronate수율 54%

시약·촉매·용매 3

HCID 3283Diethyl Ether용매HCID 8028Tetrahydrofuran용매2회HCID 8058Hexane용매

실험 절차

n-BuLi (2.5 mL of a 2.5 M solution in hexane, 6.23 mmol) was added dropwise with stirring to a solution of 6 (1.51 g, 5.93 mmol) in THF (9.5 mL) at −78° C. under argon. After 30 min a solution of trimethylborate (0.7 mL, 5.93 mmol) in THF (2 mL) was added and the mixture stirred for 1.5 h; thereafter, the resulting yellow solution was quenched with TMSCl (0.75 mL, 5.93 mmol) and allowed to reach rt. After 1 h (+)-pinanediol (1.01 g, 5.93 mmol) dissolved in a minimum amount of anhydrous Et2O was added one portion to the solution, and then stirred overnight. The reaction mixture was partitioned in Et2O (16 mL) and H2O (10 mL) and the aqueous phase extracted with Et2O (2×10 mL). The combined organic phases were dried on MgSO4, filtered and concentrated to give an orange oil, which was purified by chromatography (7:3 EtPet/EtOAc) and crystallization (EtPet), affording 7 (1.14 g, 54%) as a white crystalline solid, mp 98-101° C., [α]D=+11.2 (c 1.5, CHCl3). IR (KBr): 1646 cm˜1. 1H NMR (CDCl3): δ 0.81 (3H, s, pinanyl CH3), 1.22 (1H, d, J=10.5 Hz, pinanyl Hendo), 1.33 (3H, s, pinanyl CH3), 1.40 (6H, s, 2CH3), 1.50 (3H, s, pinanyl CH3), 1.5-2.5 (5H, m, pinanyl protons), 4.22 (2H, s, CH2O), 4.47 (1H, dd, J=8.8, 2.0 Hz, pinanyl CHOB), 7.43 (1H, t, J=7.7 Hz, H5 arom.), 7.92 (1H, dt, J=7.7, 1.5 Hz, H6 arom.), 8.05 (1H, dt, J=7.7, 1.5 Hz, H4 arom.), 8.43 (1H, br s, H2 arom.). 13C NMR (CDCl3): δ24.4, 26.9, 27.5, 28.8 (2C), 29.1, 35.9, 38.6, 40.0, 51.9, 68.0, 78.8, 79.5, 86.8, 128.1, 131.2, 135.0, 137.8, 162.5, (CB and aromatic quaternary C not seen). EI-MS: m/z 353 (M+), 338 (base peak), 323, 282, 242, 202, 186, 130, 103, 67, 55. Anal. Calcd for C21H28NO3B: C, 71.39; H, 7.99; N 3.96. Found: C, 71.01; H, 8.65; N, 3.89.

후처리

  1. customto reach rt
  2. additionwas added one portion to the solution
  3. stirringstirred overnight
  4. customThe reaction mixture was partitioned in Et2O (16 mL)
  5. extractionH2O (10 mL) and the aqueous phase extracted with Et2O (2×10 mL)
  6. customThe combined organic phases were dried on MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customto give an orange oil, which
  10. customwas purified by chromatography (7:3 EtPet/EtOAc) and crystallization (EtPet)

출처 및 근거

ORD 기록
ord-a0d9be2138254b09bcdf42e11d864971
출처 데이터셋
uspto-grants-2011_04
특허 번호
US07928129B1

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