Sodium borohydride → HCID 67591872, compound

Participants

Reaction Steps

To a suspension of the title product of Example 63 (1.85 g, 0.00447 mol) in 70 ml of methanol at 0-5° C. was added in portions 208 mg (0.00538 mol) of sodium borohydride. The reaction was warmed with stirring to room temperature, then diluted with 20 ml of tetrahydrofuran to obtain a homogeneous mixture, which, after stirring for 1.2 hours was concentrated in vacuo and the residue taken up in 400 ml ethyl acetate, washed with H2O and brine, dried over Na2SO4 and concentrated in vacuo to a yellow-white foam. Purification was carried out by silica gel column chromatography eluting with 20% ethyl acetate/CH2Cl2. The less polar cis-title product was isolated as a white solid (1.11 g, 60%). Recrystallization from isopropanol/hexanes gave 1.04 g of white crystals, m.p. 144-146° C. The more polar trans-title product was obtained as a mixture, contaminated with a small amount of the less polar product. It was re-chromatographed using the same eluant to yield 400 mg (22%) of trans-title product as a white foamy solid. Recrystallization from toluene-hexanes afforded 280 mg of white crystals, m.p. 100-102° C.

Provenance & Evidence