Benzyl chloroformate → HCID 86609034, compound

HRID 13723Notes

Reaction equation

HRID 13723 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Na+].[CH2:11]([C@@H:15]1[C@@H:18]([CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[O:17][C:16]1=[O:24])[CH2:12][CH2:13][CH3:14].[CH2:25]([O:32][C:33](Cl)=[O:34])[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1>C1COCC1>[CH2:11]([C@@:15]1([C:33]([O:32][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)=[O:34])[C@H:18]([CH2:19][CH2:20][CH2:21][CH2:22][CH3:23])[O:17][C:16]1=[O:24])[CH2:12][CH2:13][CH3:14]

Participants

5

Reactant 3

HCID 10387Benzyl chloroformateHCID 2724254Sodium bis(trimethylsilyl)amideHCID 59340438HCID 59340438, compound

Product 1

HCID 86609034HCID 86609034, compoundYield 76.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
23 °C

Procedure

To a −78° C. solution of NaHMDS (1.2 equiv, 0.91 mmol, 45 μL, 2M in THF) in 5 mL THF was added 150 mg (0.73 mmol) of β-lactone 3a dissolved in 2.5 mL THF. After 1.5 h, benzylchloroformate (1.1 equiv, 0.833 mmol, 120 μL) was added at one time and stirred for an additional 3 h. This solution was warmed to 23° C. over 1 h and worked up as described above for β-lactone 8b. Flash chromatography on SiO2 (5 % Et2O: hexanes) gave β-lactone 8c (185 mg, 74% yield) as a colorless oil: Rf 0.48 (15% Et2O : Hexanes ); IR (thin film) 1824, 1757, 1716 cm−1; 1H NMR (300 MHz, CDCl3) δ 7.40 (m, 5H), 5.27, 5.22 (AB q, J=12.0, 2H), 4.52 (dd, J=4.8, 8.4 Hz, 11H), 2.50-2.56 (m, 1H), 2.22-2.30 (m, 2H), 1.71-1.85 (m, 1H), 1.44-1.60 (m, 4H), 1.15-1.39 (m, 8H), 0.81-0.92 (m, 6H); 13C NMR (500 MHz, CDCl3) 14, 14.6, 14.7, 23.1, 23.3, 23.6, 24.9, 25.8, 26.9, 29.4, 30.4, 31.1, 31.9, 32.3, 40.4, 71.6, 79.8, 121.7, 129.2, 129.4, 129.5, 129.8, 133.1, 152.7, 163.7, 167.3; ESI LRMS Calcd. for C20H28LiO4+[M+Li]:339. Found: 338.

Sources & evidence

ORD record
ord-b21a38f6484b456c83558945e5498e10
Source dataset
uspto-grants-2010_06
Patent number
US07728153B2

Reaction notes

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