Trioxobis(pyridine)chromium → 17beta-Formyl-6-t-butylcarboxy-6-azaandrost-4-en-3-one

Participants

Reaction Steps

A solution of 17β-hydroxymethyl-3β-hydroxy-6-t-butylcarboxy-6-azaandrost-4-ene (182 mg, 0.448 mmol), prepared in part A above, in methylene chloride (7 mL) is added to freshly prepared Collins' reagent. (CrO3 ·2 pyridine) in methylene chloride (12 mL) at 0° C. After 15 minutes the solvent is decanted from the tar, the tar is triturated with methylene chloride (2×30 mL), the combined methylene chloride washed with 2N NaOH, saturated aqueous NaHSO4, saturated aqueous NaCl, dried over MgSO4, concentrated and chromatographed on silica gel (50% ehtyl acetate/hexanes) to give crude 17β-formyl-6-t-butylcarboxy-6-azaandrost-4-en-3-one of sufficient purity to carry on to the following steps; yield: 125 mg (69%).

Provenance & Evidence