Synthesis of steroidal D-ring fused pyrazolines: study of regiochemistry of addition.
The addition of diphenylnitrilimine and C-o-chlorodiphenylnitrilimine to 3 beta-hydroxyandrost-5,16-diene (3b) produced a 1/1 ratio of regioisomeric, 1,3-diaryl-2-pyrazolines (6a, 7a and 6b, 7b), whereas the addition of N-o-chlorodiphenylnitrilimine gave a 5/1 ratio in favor of the [17 alpha, 16 alpha-d] regioisomer (7c). To further delineate the factors governing the regiochemistry of addition of diphenylnitrilimines to steroid 16-enes, additions were carried out on 16-acetyl-5 alpha-androst-16-ene (5b) and 1-acetylcyclopentene (10).
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Department of Chemistry, University of Maine, Orono 04469.
Sheu
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D000736:Androstenes / Q000737:chemistry; D000737:Androstenols / Q000737:chemistry; D001547:Benzaldehydes / Q000737:chemistry; D003500:Cyclization; D003517:Cyclopentanes / Q000737:chemistry; D006835:Hydrazones / Q000737:chemistry; D007536:Isomerism; D007659:Ketones / Q000737:chemistry; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry
C090613:16-acetylandrost-16-ene; C090612:3-hydroxyandrost-5,16-diene; D000736:Androstenes; D000737:Androstenols; D001547:Benzaldehydes; D003517:Cyclopentanes; D006835:Hydrazones; D007659:Ketones; D011720:Pyrazoles; C006981:alpha-chlorobenzaldehyde phenylhydrazone; C090611:1-acetylcyclopentene