Androsta-4,6-diene-3,17-dione → HCID 56636077, compound
Reaction equation
[CH3:1][C@:2]12[CH2:19][CH2:18][C@H:17]3[C@@H:7]([CH:8]=[CH:9][C:10]4[C@:15]3([CH3:16])[CH2:14][CH2:13][C:12](=[O:20])[CH:11]=4)[C@@H:6]1[CH2:5][CH2:4][C:3]2=[O:21].[CH3:22][Mg]Br>>[CH3:22][C@@H:8]1[CH:9]=[C:10]2[C@:15]([CH3:16])([CH2:14][CH2:13][C:12](=[O:20])[CH2:11]2)[C@@H:17]2[C@@H:7]1[C@H:6]1[C@@:2]([CH2:19][CH2:18]2)([CH3:1])[C:3](=[O:21])[CH2:4][CH2:5]1Participants
Procedure
Alkylation of androsta-4,6-dien-3,17-dione 17 ketal 1 with methyl magnesium bromide in the presence of cuprous chloride, proceeds via conjugate addition to yield 7α-methylandrost-5-en-3,17-dione 17 ketal 2. Allylic bromination of 2 using N-bromosuccinimide in carbon tetrachloride yields the 66-bromo-7α-methylandrost-4-en-3,17-dione 17 ketal 3. Lithium aluminum hydride reduction of the ketone in 3 with concomitant double bond migration and loss of bromide should yield 4. Deprotection of the C-17 ketone with aqueous acid yields 3β-hydroxy-7α-methylandrost-5-en-17-one, 5. Higher homologues may be synthesized using the substituted Grignard reagent i.e. R=CH3, C2H5, C3H7. The 7β-epimer can be synthesized by treatment of 2 with DDQ--dichlorodicyanoquinone to generate another olefin at C-7. Catalytic reduction of this olefin should occur from the a face of the steroid to yield the 7β-methyl steroid i.e. 7β-methylandrost-5-en-3,17-dione 17 ketal. Following the same sequence as above yields 3β-hydroxy-7β-methylandrost-5-en-17-one. ##STR20##
Sources & evidence
- ORD record
- ord-50ec66408783491ebedf4900db69caa8
- Source dataset
- uspto-grants-1998_09
- Patent number
- US05804576
Reaction notes
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