Results 131 to 140 of about 173,508 (193)
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2023
Steroids are organic compounds with four rings arranged in a precise molecular configuration and are involved in many biological functions displaying a wide spectrum of biological activities and diverse chemical reactivities. Structural modifications of the steroidal rings have attracted a considerable amount of attention recently.
Mukesh M. Mudgal, Mangesh M. Mudgal
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Steroids are organic compounds with four rings arranged in a precise molecular configuration and are involved in many biological functions displaying a wide spectrum of biological activities and diverse chemical reactivities. Structural modifications of the steroidal rings have attracted a considerable amount of attention recently.
Mukesh M. Mudgal, Mangesh M. Mudgal
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Heterocyclic steroids. Steroidal pyrimidines
Experientia, 1963Die erste Synthese eines Steroid-Analogen, in welchem Ring A zu einem Pyrimidin umgewandelt wurde, wird beschrieben. Die wichtigste Zwischenstufe 4b wurde durch Abbau von 19-nor-Testosteron gewonnen. Kondensation von 4b mit Thioharnstoff fuhrte zu 17β-Acetoxy-2,4-diazaestr-4-en-1-on-3-thion (5).
E, CASPI, D M, PIATAK
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Tetrahedron Letters, 1966
Abstract The acetylester (Ib) has been transformed into several derivatives. The direction of bromination of the 4-ketone under acid conditions has been shown as proceeding toward C-3 by the isolation of bromosteroids (Ic) and V. In addition, the 2-oxa lactone (III) has been prepared.
J.G. Westra +3 more
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Abstract The acetylester (Ib) has been transformed into several derivatives. The direction of bromination of the 4-ketone under acid conditions has been shown as proceeding toward C-3 by the isolation of bromosteroids (Ic) and V. In addition, the 2-oxa lactone (III) has been prepared.
J.G. Westra +3 more
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Heterocyclic steroids V. 2,4-diaza steroids
Steroids, 1964Abstract A new route to methyl 17β-acetoxy-1,5-seco-2,3,4-trisnorestr-5-one-1-oate has been developed. This β-ketoester has been used for the synthesis of steroidal pyrimidines.
D.M. Piatak, E. Caspi
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Polynuclear heterocyclic systems. Part V: Heterocycles related to steroids and C‐nor‐steroids
Recueil des Travaux Chimiques des Pays-Bas, 1968AbstractThe preparation of 6‐methoxy‐2‐(2′‐oxocyclopentyl‐1‐tetralone (I) and 2‐(2′‐oxocyclopentyl)quinolizidin‐1‐one (II) is described. Diketones I and II have been converted to heterocyclic systems related to steroids and C‐nor‐steroids.
R. van Hes +3 more
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Total synthesis of heterocyclic steroids
J. Chem. Soc., Perkin Trans. 1, 1983The total synthetic approach developed initially for natural steroids, and used for the preparation of A-nor compounds, has been extended to the preparation of novel heterocyclic steroids. The easily accessible 3,4-dinor-2,5-seco-9α-estrane-1,5,17-trione (9a) was treated with hydrazine hydrate, urea, and hydroxylamine hydrochloride to provide the 1 ...
Yu Ding, Bahman Nassim, Pierre Crabbé
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Novel heterocyclic steroidal amines
Journal of the Chemical Society D: Chemical Communications, 1969Interrelated photochemical and thermal reaction sequences are outlined with novel stereochemical or other mechanistic features leading to derivatives of 6β,19-imino-5α- and -5β-cholestanes (I and II) and a range of aza-steroids such as (VIII) containing 2-methylpiperidine residues.
A. M. Farid +3 more
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DERIVATIVES OF STEROIDS WITH CONDENSED HETEROCYCLES
Russian Chemical Reviews, 1967CONTENTS I. Introduction 311 II. Five-membered heterocycles with one heteroatom 312 III. Five-membered heterocycles with two heteroatoms 314 IV. Five-membered heterocycles with three heteroatoms 319 V. Six-membered heterocycles with one heteroatom 320 VI. Six-membered heterocycles with two heteroatoms 320 VII.
A A Akhrem, Yu A Titov
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Preparation and androgenic activity of novel heterocyclic steroids
Experientia, 1970Die Darstellung verschiedener A-Nor-5α-androstan-Verbindungen, die im A-Ring ein Schwefel-, Selen- oder Tellur-Atom haben, wird beschrieben. Sie besitzen, im Gegensatz zu den entsprechenden Oxa-Verbindungen, anabol-androgene Aktivitat. 2, 3-Dithia-5α-androstan-17β-ol-Acetat hatte ebenfalls hohe anabol-androgene Wirksamkeit.
M E, Wolff, G, Zanati
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Heterocyclic steroids: Synthesis of steroidal selena, tellura, and thia lactones of estrane series
Steroids, 1996A successful approach in the synthesis of 3 beta-acetoxy-17a-selena-D-homo-1,3,5(10)-estratrien-17 -one (5), 3 beta-acetoxy-17a tellura-D-homo-1,3,5(10)-estratrien-17-one (6), and 3 beta-acetoxy-17a-thia-D-homo-1,3,5(10)-estratrien-17-one (7) was achieved from 3 beta-acetoxy-1,3,5(10)-estratrien-17-one (1).
A U, Siddiqui +3 more
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