HCID 19782754, compound → HCID 19782752, compound

HRID 258180Notes

Reaction equation

HRID 258180 reaction equation
[H-].[H-].[H-].[H-].[Li+].[Al+3].[CH3:7][O:8][CH:9]([CH2:17][CH3:18])[CH2:10][CH2:11][CH2:12][C:13](OC)=[O:14]>O(CC)CC>[CH3:7][O:8][CH:9]([CH2:17][CH3:18])[CH2:10][CH2:11][CH2:12][CH2:13][OH:14]

Participants

4

Reactant 2

HCID 19782754HCID 19782754, compound2×HCID 21226445Aluminium lithium hydride

Product 1

HCID 19782752HCID 19782752, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Conditions

Temperature
0 °C

Procedure

A stirred suspension of LiAlH4 (15.2 g, 0.40 mole) in dry OEt2 (700 mL) was cooled to 0° C. Methyl 5-methoxyheptanoate (Compound XXII, 34.8 g, 0.20 mole) in dry OEt2 (100 mL) was added dropwise over 1/2 h. The reaction was allowed to slowly warm to room temperature and stirred for an additional 12 h. The excess hydride was destroyed by dropwise addition of sat. aqueous Na2SO4 (extremely vigorous reaction) to the rapidly stirred reaction mixture until the gray color was completely destroyed and only a snow white precipitate remained (further addition of sat. Na2SO4 increased the water content of the product and necessitated drying before the next reaction). The precipitate was filtered and washed with dry OEt2 (5×300 mL). Removal of the ether gave 5-methoxy-1-heptanol (Compound XXIII, 29.2 g, 100%) as a colorless oil, sufficiently pure for further reactions: IR (film) cm-1 3390, 2970, 2945, 2875, 2830, 1465, 1440, 1380, 1200, 1170, 1135, 1094, 1060, 1040, 918; 1H NMR (200 MHz, CDCl3) δ 3.66 (m, 2H), 3.33 (s, 3H), 3.10 (rough pentet, 1H), 1.74 (s, 1H), 1.3-1.7 (complex, 8H), 0.89 (t, 7.4 Hz, 3); 13C NMR (22.5 MHz, CDCl3) δ 82.2, 62.4, 56.4, 32.8, 32.8, 25.8, 21.6, 9.4; high resolution mass spectrum (70 eV) m/e 146 (M+, not observed), 117.0918 (M+ - CH3CH2., calculated 117.0916 for C6H13O2); TLC (OEt2, vanillin dip) Rf =0.30.

Workup

  1. temperatureto slowly warm to room temperature
  2. customThe excess hydride was destroyed by dropwise addition of sat. aqueous Na2SO4 (
  3. customextremely vigorous reaction)
  4. customto the rapidly stirred reaction mixture until the gray color
  5. customwas completely destroyed
  6. additionfurther addition of sat. Na2SO4
  7. temperatureincreased the water content of the product
  8. customnecessitated drying before the next reaction)
  9. filtrationThe precipitate was filtered
  10. washwashed with dry OEt2 (5×300 mL)
  11. customRemoval of the ether

Sources & evidence

ORD record
ord-b6439bece37445e6b51fb9ad23066d2e
Source dataset
uspto-grants-1993_11
Patent number
US05264619

Reaction notes

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