(2-Iodoethoxy)triisopropylsilane → (5R,6S)-3-Allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-(cyclopropylmethyl)-3-(2-(triisopropylsilyloxy)ethyl)piperidin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 3.70 g (8.9 mmol) of a mixture of C-3 diastereomers of (5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-(cyclopropylmethyl)piperidin-2-oneoxopentanoate (Example 35, Step B) and 20.7 g (63 mmol) of (2-iodoethoxy)triisopropylsilane in dry, degassed THF (60 mL) was added 54.5 mL (54.5 mmol) of a 1 M solution of lithium bis(trimethylsilyl)amide in THF slowly via syringe over 6 min. After 10 min, the orange solution was warmed to 40° C. and stirred for an additional 2.25 h. The reaction was cooled to room temperature, quenched with saturated aqueous ammonium chloride, and extracted with EtOAc (3×). The combined organic layers were dried over Na2SO4, filtered and the filtrate was concentrated. Purification of the residue by flash chromatography on silica gel (2-25% EtOAc/hexanes, gradient elution) provided the title compound (mixture of C-3 epimers) as a light yellow oil.

Provenance & Evidence