Addition to steroid polyenes IV : Ring D-fission and ring C-aromatization in 4,4-dimethyl-Δ5,7-steroidal systems
✍ Scribed by J. Lakeman; W.N. Speckamp; H.O. Huisman
- Publisher
- Elsevier Science
- Year
- 1967
- Tongue
- French
- Weight
- 206 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
Pergemea Press Ltd* Printed in Great Britain. ADDITIOD TG SaOID POLYHDS IV' Diag D-fi88ion and riag kroutivtioa in 4,4-diaetbl-,5t7 -8toroidal 8yrtem J.Lakeaaa2, T.I.Speokaap aad 8.O.Huiman Laboratory for Organic Cheai8tm uaiVOr8ifi Of k8tOrdu, 1i8u+O Achtergraoht 129, ~8tOrd.S& The Deth8rl8nd8. Ia th8 oour8e of our iatertiptiona on addition of diuthyl-rsodicarboxylste to eteroidal polyene83 the letter reaction has been carried out with a number of 4,4dimethyl-b5'7-dieaee, the reralte of which will be published in the near _%ture. During these inreetigations a remarkably facile C,3-C,7 OII-fission has been ob8erved, which in acidic medium occurs to 4,4-dimethyl-AT'!-proge8teroae in hi& yield, uad8r relatively mild re&ction CirCUm8taaCes. in this; coaunication a dee-OriptiOn Of this fission proce88, which is followed by ring ~C-aromntixetioa, wiil be given. Oxidation of 7-dehydrooholerterol (Is) with eluminlum iso~ropoxide/cyclohexanone in toluene4 gave a mixture of the dienone 11s [, ",z 1660 cm" (carbonylj; b T!$l 3 0.59 singlet (C,G -CH3), 1.15 8inglet (C,g-CH3!],and 111s [Q z 1700 cm-' (cerbo-nJl)r b g;, , 0.59 singlet 3 (Cie-CH,), 1.15 singlet (C,9-CHJ)], which upon met&letion with rethyliodide/pote88iur butoxide 5 afforded the 4,4-dinethyl-5,?-diene IVae [r.p. 156-152'; 9 ",' 1700 cm" (carbonyl); b zl 0.59 sidglet (C,8-CH3;, I.15 8inglet (C,g-CH3); A _ EtoH 273 (9.700), 262 (rO.COO{, 294 (5.500) cm] in high yields.