Ethyl 11-bromoundecanoate → Ethyl 17-(tetrahydropyran-2-yl-oxy)-heptadecanoate

Participants

Reaction Conditions

Reaction Steps

From (38) and (76). Zinc powder (166 mg, 2.55 mmol) was dried at 70° C. for 30 min in a sealed tube, then DMA (2.5 ml) and solid 12 (22 mg, 0.09 mmol) were added. After stirring for 10 min, neat ethyl 11-bromoundecanoate (500 mg, 1.7 mmol) was added and the reaction mixture was stirred in the sealed tube for 10 h at 80° C. In a 10-ml flask, NiCl2-glyme (29 mg, 0.13 mmol) and (R)-(i-Pr)-Pybox (or (S)-(i-Pr)-Pybox) (51 mg, 0.17 mmol) were dissolved in DMA (1.5 ml) and THF (0.5 ml), then neat I(CH2)6OTHP 38 (410 mg, 1.31 mmol) was added. This mixture was cooled to 0° C. and organozinc solution 76 was added via cannula. The reaction mixture was allowed to warm to the room temperature over period of 12 h and stirred at room temperature for additional 12 h. The reaction was quenched by addition of aqueous NH4Cl, extracted with EtOAc, the extract was dried over Na2SO4 and evaporated. The crude product was purified by silica gel chromatography in hexane-EtOAc (98:2, 97:3, 96:4) to afford the product ethyl 17-(tetrahydropyran-2-yl-oxy)-heptadecanoate 78 (369 mg, 71%).

Provenance & Evidence