Benzene → (-)-(10R)-3,3,8,8,10-Pentamethyl-1,5-dioxaspiro[5,5]undecan-9-one

HRID 1589994노트

반응식

HRID 1589994 반응식
[CH3:1][C:2]1([CH3:11])[CH2:7][C:6](=[O:8])[CH2:5][C@@H:4]([CH3:9])[C:3]1=[O:10].[CH3:12][C:13]([CH3:18])([CH2:16]O)[CH2:14][OH:15].C1C=CC=CC=1>O>[CH3:12][C:13]1([CH3:18])[CH2:14][O:15][C:6]2([CH2:5][C@@H:4]([CH3:9])[C:3](=[O:10])[C:2]([CH3:1])([CH3:11])[CH2:7]2)[O:8][CH2:16]1

참가 물질

5

반응물 3

HCID 241BenzeneHCID 31344Neopentyl glycolHCID 10176229Levodione

생성물 1

HCID 14702805(-)-(10R)-3,3,8,8,10-Pentamethyl-1,5-dioxaspiro[5,5]undecan-9-one수율 99.2%

시약·촉매·용매 1

HCID 962Water용매

실험 절차

A mixture of (-)-(6R)-2,2,6-trimethyl-1,4-cyclohexandione (924 mg, 6.0 mmol), 2,2-dimethyl-1,3-propandiol (791 mg, 7.6 mmol), pyridinium p-tosylate (34 mg, 0.13 mmol), and benzene (15 mL) was heated to reflux under a Dean-Stark water separator for 4 h. The reaction mixture was allowed to cool to room temperature before it was washed with H2O, and dried over anhydrous Na2SO4. Evaporation of solvent gave a pale yellow oil (1.43 g) as the crude product, which was distilled using the Kugel-rohr apparatus (80°-100° C., 0.03 mm Hg) to give pure ketal as a colorless oil (1.31 g, 91%), [a]D -87.7° C. (c 1.10, CH3OH); ir: 1710 cm-1; 1H nmr d: 0.85 (s, 3H, CH3), 0.91 (d, J=6.6 Hz, 3H, CHCH3), 0.97 (s, 6H, 2 CH3), 1.16 (s, 3H, CH3), 1.56 (dd, J=13.5, 13.5 Hz, H-11ax), 1.58 (d, J=14.2 Hz, H-7ax), 2.38 (ddd, J=13.5, 5.3, 3.8 Hz, 1H, H-11eq), 2.47 (dd, J=14.2, 3.8 Hz, 1H, H-7eq), 2.85 (m, 1H, CHCH3), 3.41 and 3.48 (2dd, J=11.4, 1.6 Hz, 2H, 2 equatorial H at C2 and C4), 3.53 and 3.61 (2d, J=11.4 Hz, 2H, 2 axial H at C2 and C4); ms m/e: 240 (M+, 0.58), 141 (27), 155 (98), 83 (27), 69 (100).

후처리

  1. temperaturewas heated
  2. washwas washed with H2O
  3. dry with materialdried over anhydrous Na2SO4
  4. customEvaporation of solvent

출처 및 근거

ORD 기록
ord-0748fe3ad6d74b978b82c161f06bdc3c
출처 데이터셋
uspto-grants-1993_04
특허 번호
US05201931

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