Selective C-2 Acetylation of Steroidal Aromatic A Rings
26 February 2002 (online)
Exclusive and high-yield C-2 acetylation of the A ring of aromatic steroids is achieved with acetyl methanesulfonate. A short access to 2-hydroxyestrone 3-methyl ether (7) and 2-hydroxyestrone (8) is established. The same reagent allows the assembly of a 2-acetyl-C,18-bisnor-13α,17α-estradiol derivative 3 in a one-pot procedure, which comprises three mechanistic steps from an ACD precursor 1. Similarly, formation of 1-acetyl-cycloalkenes from cyclopentene and cyclohexene can be performed with acetyl methanesulfonate.