Iodine → Tetrahydro-2-(17-acetoxyheptadecyloxy)-2H-pyran

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 10-ml Schlenk tube, zinc powder (98 mg, 1.5 mmol) was dried at 70° C. under high vacuum for 30 min. After back-filling with nitrogen, DMI (1 ml) and iodine (13 mg, 0.05 mmol) were added. The mixture was stirred until disappearance of the iodine color, after which neat 11-bromoundecyl acetate (293 mg, 1 mmol) was added. The tube was sealed, and the mixture was stirred at 70° C. for 12 h, cooled to the room temperature and zinc excess was allowed to settle. In a 5-ml flask, NiCl2.glyme (17 mg, 0.08 mmol) and (R)-(i-Pr)-Pybox (or (S)-(i-Pr)-Pybox) (30 mg, 0.1 mmol) were dissolved in DMI (1 ml) and THF (0.3 ml), then neat I(CH2)6OTHP 38 (240 mg, 0.77 mmol) was added followed by addition of the organozinc solution 33 via cannula. Reaction mixture was stirred at room temperature for 14 h, quenched with NH4Cl and extracted with EtOAc. Extract was dried over Na2SO4 and concentrated by solvent evaporation. Chromatography in hexane-ethyl ether (15:1, 10:1) gave the product, 212 mg (69%).

Herkunft & Nachweise