The stereochemistry of the 1,2-addition of Grignard reagents to some steroidal unsaturated ketones

The stereochemistry of 3β,17β-dihydroxy-3a-ethylandrost-4-ene, 3α,17β-dihydroxy-3β-methylestr-4-ene and 3β-acetoxy-7α,17β-dihydroxy-7β-methylandrost-5-ene, which were obtained by Grignard reactions from the corresponding αβ-unsaturated ketones, have been established by X-ray crystallography.