Ethyl 6-bromohexanoate → Ethyl 17-(tetrahydropyran-2-yl-oxy)-heptadecanoate

Participants

Reaction Conditions

Reaction Steps

From (77) and (36). Zinc powder (342 mg, 5.27 mmol) was dried at 70° C. for 30 min in a sealed tube, then DMA (2 ml) and solid 12 (45 mg, 0.18 mmol) were added. After stirring for 10 min, neat ethyl 6-bromohexanoate (0.63 ml, 3.52 mmol) was added and the reaction mixture was stirred in the sealed tube for 10 h at 75° C. In a 10-ml flask, NiCl2-glyme (52 mg, 0.23 mmol) and (R)-(i-Pr)-Pybox (or (S)-(i-Pr)-Pybox) (92 mg, 0.31 mmol) were dissolved in DMA (1.5 ml), cooled to 0° C. and solution of I(CH2)11OTHP 77 (896 mg, 2.34 mmol) in DMA (0.5 ml) was added. Then the solution of organozinc reagent 36 was added. The reaction mixture was stirred at 0° C. for 6 h and at room temperature for 6 h, then quenched by addition of aqueous NH4Cl, extracted with EtOAc, extract was dried over Na2SO4 and evaporated. The crude product was purified as in Method 1 to give compound 78 (888 mg, 95%).

Provenance & Evidence