Hexamethylphosphoramide → 6-(5-(t-Butyldimethylsilyloxy)pentan-2-yl)-4-hydroxy-3-propionyl-2-H-pyran-2-one
Reaction equation
[CH2:1]([C:3]1[O:8][C:7](=[O:9])[C:6]([C:10](=[O:13])[CH2:11][CH3:12])=[C:5]([OH:14])[CH:4]=1)[CH3:2].[Li+].CC([N-]C(C)C)C.Br[CH2:24][CH2:25][CH2:26][O:27][Si:28]([C:31]([CH3:34])([CH3:33])[CH3:32])([CH3:30])[CH3:29].CN(P(N(C)C)(N(C)C)=O)C>C1COCC1>[Si:28]([O:27][CH2:26][CH2:25][CH2:24][CH:1]([C:3]1[O:8][C:7](=[O:9])[C:6]([C:10](=[O:13])[CH2:11][CH3:12])=[C:5]([OH:14])[CH:4]=1)[CH3:2])([C:31]([CH3:34])([CH3:33])[CH3:32])([CH3:30])[CH3:29]Participants
6
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
6-Ethyl-4-hydroxy-3-propionyl-2-H-pyran-2-one (III; 0.5 g; 2.56 mmol) was dissolved in 20 ml anhydrous THF and cooled to 0° C. under argon. To the cooled solution, was added LDA (5.12 ml of 1.5 M in cyclohexane; 7.68 mmol; Aldrich) and the reaction mixture was stirred for 30 min. To the cooled reaction mixture, was added 3-bromopropoxy-t-butyldimethylsilane (0.77 g; 3.07 mmol; Aldrich) and 1 ml HMPA (Aldrich). The reaction mixture was stirred for 30 min at 0° C., quenched with saturated NH4Cl, extracted with 3×20 ml EtOAc, dried with anhydrous Na2SO4, and evaporated to an oil. The product was purified via silica chromatography (10% EtOAc in hexanes).
Workup
- customTo the cooled reaction mixture
- stirringThe reaction mixture was stirred for 30 min at 0° C.
- customquenched with saturated NH4Cl
- extractionextracted with 3×20 ml EtOAc
- dry with materialdried with anhydrous Na2SO4
- customevaporated to an oil
- customThe product was purified via silica chromatography (10% EtOAc in hexanes)
Sources & evidence
- ORD record
- ord-1ed33d85521b46928b410a9af18322e7
- Source dataset
- uspto-grants-2015_09
- Patent number
- US09133155B2
Reaction notes
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