HCID 69997935, compound → HCID 56994186, compound

Participants

Reaction Steps

—Pyridinium chlorochromate (8.79 g) was added to a solution of (3β,5α,20S)-4,4,20-trimethylpregna-8,14-diene-3,21-diol 3-benzoate (Example 7, step ii; 12.6 g) in dry dichloromethane (130 ml). The reaction mixture was stirred at room temperature for 1.5 h. Another portion of pyridinium chlorochromate (1.50 g) was added and stirring was continued for another 1.5 h. The reaction mixture was filtered and the filtrate was poured into a saturated aqueous solution of sodium hydrogencarbonate. The product was extracted into dichloromethane and the combined organic phases were washed with water, dried over magnesium sulfate and concentrated under reduced pressure, to afford (3β,5α,20S)-3-(benzoyloxy)-4,4-dimethylpregna-8,14-diene-20-carboxaldehyde (10.3 g). The product was used in the following step without further purification.

Provenance & Evidence