Methyl iodide → HCID 18649291, compound

Participants

Reaction Steps

With reference to Scheme 4, alkylation of 1a, such as 20-hydroxy-4-pregnen-3-one, using potassium t-butoxide and methyl iodide yields 4-methyl-20-hydroxy-4-pregnen-3-one 1b. Allylic bromination of N-bromosuccinimide in carbon tetrachloride yields the 6β-bromo derivative. Protection of the C-20 alcohol as its t-butyldimethyl silyl derivative yields 3. Lithium aluminum hydride reduction of the ketone in 3 with concomitant double bond migration and loss of bromide should yield 4. Protection of the C-3 alcohol as a tetrahydropyranyl ether, followed by deprotection and oxidation of the C-17 alcohol should yield the C-17 ketone 7. Removal of the C-3 tetrahydropyranyl ether yields 4α-methyl-5-pregnen-20-one.

Provenance & Evidence