Pyridine → (1S)-1,3-Dimethyl-2-oxobutyl (2R)-4-[(3-chloropropyl)sulfonyloxy]-3,3-dimethyl-2-(1,1,2,2-tetramethyl-1-silapropoxy)butanoate

HRID 1919426노트

반응식

HRID 1919426 반응식
[Cl:1][CH2:2][CH2:3][CH2:4][S:5]([O:8][CH2:9][C:10]([CH3:24])([CH3:23])[C@@H:11]([O:15][Si:16]([CH3:22])([CH3:21])[C:17]([CH3:20])([CH3:19])[CH3:18])[C:12]([OH:14])=[O:13])(=[O:7])=[O:6].C(Cl)(=O)C(Cl)=O.O[C@H:32]([C:34](=[O:38])[CH:35]([CH3:37])[CH3:36])[CH3:33].N1C=CC=CC=1>ClCCl>[Cl:1][CH2:2][CH2:3][CH2:4][S:5]([O:8][CH2:9][C:10]([CH3:24])([CH3:23])[C@@H:11]([O:15][Si:16]([CH3:22])([CH3:21])[C:17]([CH3:19])([CH3:18])[CH3:20])[C:12]([O:14][C@@H:32]([CH3:33])[C:34](=[O:38])[CH:35]([CH3:37])[CH3:36])=[O:13])(=[O:7])=[O:6]

참가 물질

6

반응물 4

HCID 1049PyridineHCID 65578Oxalyl chlorideHCID 45085102(2S)-2-hydroxy-4-methylpentan-3-oneHCID 86628876(2R)-4-[(3-Chloropropyl)sulfonyloxy]-3,3-dimethyl-2-(1,1,2,2-tetramethyl-1-silapropoxy)butanoic acid

생성물 1

HCID 86628899(1S)-1,3-Dimethyl-2-oxobutyl (2R)-4-[(3-chloropropyl)sulfonyloxy]-3,3-dimethyl-2-(1,1,2,2-tetramethyl-1-silapropoxy)butanoate수율 36%

시약·촉매·용매 1

HCID 6344Dichloromethane용매2회

실험 절차

Following the general procedure for the preparation of carboxylic esters from carboxylic acids of Description 15, (2R)-4-[(3-chloropropyl)sulfonyloxy]-3,3-dimethyl-2-(1,1,2,2-tetramethyl-1-silapropoxy)butanoic acid (15) (2.0 g, 5.0 mmol) dissolved in 25 mL of anhydrous dichloromethane (DCM) was reacted with 0.90 mL (1.31 g, 10 mmol) of oxalyl chloride. Upon completion of the reaction, a solution of 2 mL (1.2 g, 10.0 mmol) of (2S)-2-hydroxy-4-methylpentan-3-one (synthesized following procedures according to Gallop et al., U.S. Pat. No. 6,927,036) and 0.85 mL of pyridine (0.79 g, 10.0 mmol) in 20 mL of anhydrous dichloromethane (DCM) was added to the acid chloride. After work-up, the crude material was purified by silica gel column chromatography using a mixture of ethyl acetate (EtOAc) and hexane (Hxn) (EtOAc/Hxn=1:9) as eluent to provide 0.9 g (36% yield) of the title compound (30a) as a colorless oil. Rf=0.39 (EtOAc/Hxn=1:4). 1H NMR (400 MHz, CDCl3): δ=0.05 (s, 3H), 0.10 (s, 3H), 0.94 (s, 9H), 1.09 (s, 6H), 1.12 (d, J=7.2 Hz, 3H), 1.19 (d, J=7.2 Hz, 3H), 1.46 (d, J=7.2 Hz, 3H), 2.32-2.39 (m, 2H), 2.83 (sept., J=7.2 Hz, 1H), 3.31-3.35 (m, 2H), 3.69-3.72 (m, 2H), 4.10-4.13 (m, 3H), 5.24 (q, J=7.2 Hz, 1H) ppm. MS (ESI) m/z 501.09 (M+H)+, 523.03 (M+Na)+. The analytical data was consistent with the proposed structure.

후처리

  1. customUpon completion of the reaction
  2. customAfter work-up, the crude material was purified by silica gel column chromatography
  3. additiona mixture of ethyl acetate (EtOAc) and hexane (Hxn) (EtOAc/Hxn=1:9) as eluent

출처 및 근거

ORD 기록
ord-8ddf3d8250374de8937af2564c0d5c28
출처 데이터셋
uspto-grants-2012_05
특허 번호
US08168617B2

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