HCID 11380534, Verbindung → 2-Methylidenehexadecan-1-ol

Reaktionsgleichung

[H-].C([Al+]CC(C)C)C(C)C.[CH2:11]=[C:12]([CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][CH3:30])[C:13](OC)=[O:14].C(OCC)(=O)C.CCCCCC>C(Cl)Cl>[CH2:11]=[C:12]([CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH2:29][CH3:30])[CH2:13][OH:14]

Komponenten

Versuchsvorschrift

A solution of diisobutylaluminum hydride in CH2Cl2 (47 ml of a 1M solution, 0.047 mole, Aldrich Chem. Co.) was stirred under nitrogen in a round-bottom flask and cooled in an ice-water bath. To this was added dropwise over a period of 4 minutes a solution of 2-methylenehexadecanoic acid, methyl ester (2.82 g, 20 mmole) in CH2Cl2 (20 ml). The reaction was complete within 30 minutes as determined by TLC (20% ethyl acetate-hexane) of a sample quenched in brine-ether. The reaction was worked up after one hour by diluting with methylene chloride (300 ml) and adding several milliliters each of methanol and water. A gelatinous mass formed which broke up upon vigorous swirling. The mixture was filtered through Celite and the filtrate dried over MgSO4. Following filtration and concentration, an oily residue was obtained. The residue crystallized and was recrystallized by dissolving in hexane at room temperature then cooling in the freezer. Crystals were collected from the cold hexane by rapid filtration. 2-Methylenehexadecan-1-ol (22) was obtained in a first crop (1.718 g) of colorless crystals, mp 33°-34° C., and a second crop (0.081 g, total 1.799 g, 0.0071 mole, 71%).