Stickstoffhaltige Steroide. V. Über die epimeren 3‐Acetamino‐cholest‐4‐ene

New preparative methods using triphenylphosphine-diethyl-azodicarboxylatehydroxycompound. -Szcmnzuvy. The present paper deals with new preparative methods by lvhich thc system of triphenylpliosphinc-dicthylazodicarboxylate -hydroxycompound is treated with inany nucleophilcs. On one side, the transformation of 5 a-cholestanc-3/1-01 to t h e 3 cr-substitutcd derivatives 2a-2e (Scheme I ) by hitherto unregarded iiucleophiles like azidc, cyanide, thiocyanate, triflnoroacetatc and tliiophenoxide is shown. Further examples dcrnonstrate the great applicability of the reaction in the case of sensitive substrates. Cholesterol (5) is transforincd t o the 3cr-derivative 6a without a n y ncighhouring group participation hy thcl A5-double bond. The analogouii transformation of the hydroxysteroides 7 and 9 t o the corresponding 3 cr-substituted compounds 8a and 10a represcnt further examples to bc noted. Noteworthy is also the formation of the epi-vitamine 1)s-p-nitrobenzoate from t h e vitamin-1)s itself. On t h e other side the sources for nucleophils require spccial consideration. Scheme / demonstrates that t h c anions oi phosphoniuni salts can be used as the nuclcophils as is shown b y tliv prqm-ation of the derivatives 2a, 2c, 2f, 29, 2 h ant1 2i from .ja-cholcstanc~.?/~-ol (1). l'roni schenzr 2 oiir can prcparati\'c fact (1 + 2f, 2g, 2h, 21 and 2m) t h a t alkylhalidcs, alkylsulfittcs a n d alkylsulfonates can he used for supplying of the corresponding nucleophilc. 'Thc possibility of a direct tos!,lation of a chiral hydroxycoinpouncI with inlwsion of configuration ~-as i t is S~IOTVII by transformation of (.5'-2-l)utariol to the tosylntc, ohtained also from (I+Z-butaiiol and tosylchloride is a further rciiiarlrable point. The absence of neighbouring groul) effects allo\is also to prepare c.7s-l,2-disubstitutcd cyclohexane compounds type CsHlo (X) ( Y ) ( X = S 3 , CI, Y ~ N 3 , J ) from the corresponding tvarzs-I, 2-disubstitutcd cyclohcxanolcs C'&IO (S) (OH) ( X ~ N:j, Clj. The synthesis o i t h e compounds 14a-15d can be regarded as representative of this nc\v usc~ful inc~thodic principle.

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Stickstoffsubstituierte Steroide. VI. Epoxydierung der epimeren 3‐Acetamino‐cholest‐4‐ene und Folgereaktionen

Ponsold¹,

Preibsch²

1964

J. Prakt. Chem.

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Die epimeren 3‐Acetamino‐cholest‐4‐ene geben bei der Umsetzung mit Monoperphthalsäure von den möglichen Isomeren nur 3β‐Acetamino‐4,5β‐epoxy‐cholestan und 3α‐Acetamino‐4, 5β‐epoxy‐cholestan. Die Sauerstoffaddition erfolgt also gerichtet. Die Acetaminoepoxyde werden mit Lithiumaluminiumhydrid und durch katalytische Hydrierung zu verschiedenen Acetaminoalkoholen reduktiv gespalten.

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Stickstoffhaltige Steroide. V. Über die epimeren 3‐Acetamino‐cholest‐4‐ene

Cited by 4 publications

References 3 publications

Introduction of the Azido Group

Introduction of the Azido Group

Reaktionen mit phosphororganischen Verbindungen. XLI[1]. Neuartige synthetische Aspekte des Systems Triphenylphosphin‐Azodicarbonsäureester‐Hydroxyverbindung

Stickstoffsubstituierte Steroide. VI. Epoxydierung der epimeren 3‐Acetamino‐cholest‐4‐ene und Folgereaktionen

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