Water → (+)-5-Hydroxy-6-[(1'R)-tert-butyldimethylsilyloxy-(2'R)-methylbut-3'-enyl]-2,3-f]chromen-8-one

HRID 975536Notes

Reaction equation

HRID 975536 reaction equation
[OH:1][C:2]1[C:11]([C@H:12]([OH:17])[C@H:13]([CH3:16])[CH:14]=[CH2:15])=[C:10]2[C:5]([C:6]([CH2:19][CH2:20][CH3:21])=[CH:7][C:8](=[O:18])[O:9]2)=[C:4]2[O:22][C:23]([CH3:27])([CH3:26])[CH:24]=[CH:25][C:3]=12.N1C=CC=CC=1.[C:34]([Si:38](Cl)([CH3:40])[CH3:39])([CH3:37])([CH3:36])[CH3:35].O>C(Cl)Cl.CN(C1C=CN=CC=1)C>[OH:1][C:2]1[C:11]([C@H:12]([O:17][Si:38]([C:34]([CH3:37])([CH3:36])[CH3:35])([CH3:40])[CH3:39])[C@H:13]([CH3:16])[CH:14]=[CH2:15])=[C:10]2[C:5]([C:6]([CH2:19][CH2:20][CH3:21])=[CH:7][C:8](=[O:18])[O:9]2)=[C:4]2[O:22][C:23]([CH3:26])([CH3:27])[CH:24]=[CH:25][C:3]=12

Participants

7

Reactant 4

HCID 962WaterHCID 1049PyridineHCID 28928tert-Butyldimethylsilyl chlorideHCID 5468733(+)-5-Hydroxy-6-[(1'R)-hydroxy-(2'R)-methylbut-3'-enyl]-2,3-f]chromen-8-one

Product 1

HCID 5468734(+)-5-Hydroxy-6-[(1'R)-tert-butyldimethylsilyloxy-(2'R)-methylbut-3'-enyl]-2,3-f]chromen-8-oneYield 95.5%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of 9 (1.44 g, 3.89 mmol) in dry CH2Cl2 (50 mL) at -20° C. was added pyridine (6 mL), DMAP (1.10 g, 9.00 mmol) and tert-butylchlorodimethylsilane (1.40 g, 9.28 mmol). The reaction mixture was stirred under nitrogen at room temperature for 1.5 h until disappearance of the starting material was observed. Water (15 mL) was then added, and the mixture was stirred for an additional 15 min. The organic layer was separated, and the aqueous layer was extracted with CH2Cl2 (2×15 mL). The combined organic layers were evaporated under reduced pressure at room temperature. The oil obtained was submitted to silica gel chromatography (solvent B) to obtain 10 (1.80 g, 95%) as a syrup: [α]D20 +26° (c 3.8, acetone); 1H NMR (CDCl3): δ -0.11, 0.08 (2s, 6H, --SiCH3), 0.80 [s, 9H, --C(CH3)3 ], 0.90 (d, 3H, J=6.90 Hz, --CHCH3), 0.96 (t, 3H, J=7.30 Hz, --CH2CH3), 1.39, 1.43 (2s, 6H, --C(CH3)2), 1.60 (m, 2H, --CH2CH3), 2.54 (m, 1H, --CHCH3), 2.80 (m, 2H, --CH2CH2CH3), 4.86-5.00 (m, 2H, --CH=CH2), 5.22 [d, 1H, J=6.85 Hz, --CHOSi(CH3)2 --], 5.46 (d, 1H, J=10.0 Hz, H-3), 5.68-5.87 (m, 1H, --CH=CH2), 5.83 (s, 1H, H-9), 6.59 (d, 1H, J=10.0 Hz, H-4), 9.20 (s, 1H, Ar--OH); 13C NMR (CDCl3): δ -0.42, -0.22, 13.90, 16.14, 17.95, 23.02, 25.58, 27.47, 27.90, 38.49, 44.45, 74.08, 77.49, 102.63, 106.65, 106.72, 110.00, 115.60, 116.51, 126.61, 139.63, 150.99, 151.69, 155.33, 158.33, 160.90; Anal. Calcd for C28H40O5Si: C, 69.38; H, 8.32. Found C, 68.55; H, 8.42. MS (negative-ion FAB): m/z 483 (M-1)-, 351, 297.

Workup

  1. stirringthe mixture was stirred for an additional 15 min
  2. customThe organic layer was separated
  3. extractionthe aqueous layer was extracted with CH2Cl2 (2×15 mL)
  4. customThe combined organic layers were evaporated under reduced pressure at room temperature
  5. customThe oil obtained

Sources & evidence

ORD record
ord-98d28ff1825f438fbc1e0f4caa3571fc
Source dataset
uspto-grants-1997_03
Patent number
US05608085

Reaction notes

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