The α-alkoxycarbonylation of saturated carbonyl compounds. The synthesis of 17α-hydroxymethyl 20-keto steroids

1978 ◽  
Vol 56 (3) ◽  
pp. 410-418 ◽  
Author(s):  
D. Mukherjee ◽  
CH. R. Engel
Keyword(s):  
Free Radical ◽  
Carbonyl Compounds ◽  
Keto Group ◽  
Methyl Group ◽  
Lithium Enolates ◽  
Enol Acetates ◽  
Radical Functionalization

It is shown that enolate ions, in particular lithium enolates obtained from enol acetates of saturated ketones by reaction with methyllithium, may not only be alkylated and carboxylated, but also alkoxycarbonylated (in position a to the original saturated keto group). By this method, saturated 20-keto steroids were transformed into 17α-methoxycarbonyl 20-ketones. Thus, from pregnenolone, 17-methoxycarbonylpregnenolone was prepared and was then converted to 17-hydroxymethylprogesterone and to some of its esters. This method for preparing 17-hydroxymethylated hormone analogues of the progesterone-corticoid group is simpler and more efficient than the pathway implying a free-radical functionalization of a 17α-methyl group.

Enantioselective Radical Functionalization of Imines and Iminium Intermediates via Visible Light Photoredox Catalysis

Synthesis ◽  
2020 ◽  
Author(s):  
Jia-Jia Zhao ◽  
Hong-Hao Zhang ◽  
Shouyun Yu
Keyword(s):  
Visible Light ◽  
Asymmetric Synthesis ◽  
Carbonyl Compounds ◽  
Asymmetric Reduction ◽  
Chemical Transformations ◽  
Photoredox Catalysis ◽  
Radical Coupling ◽  
Mild Conditions ◽  
Iminium Ions ◽  
Radical Functionalization

Visible light photoredox catalysis has recently emerged as a powerful tool for the development of new and valuable chemical transformations under mild conditions. Visible-light promoted enantioselective radical transformations of imines and iminium intermediates provide new opportunities for the asymmetric synthesis of amines and asymmetric β-functionalization of unsaturated carbonyl compounds. In this review, the advance in the catalytic asymmetric radical functionalization of imines, as well as iminium intermediates, are summarized. 1 Introduction 2 The enantioselective radical functionalization of imines 2.1 Asymmetric reduction 2.2 Asymmetric cyclization 2.3 Asymmetric addition 2.4 Asymmetric radical coupling 3 The enantioselective radical functionalization of iminium ions 3.1 Asymmetric radical alkylation 3.2 Asymmetric radical acylation 4 Conclusion

BEZIEHUNGEN ZWISCHEN SUBSTITUTION IM RING A UND ABBAU IM STOFFWECHSEL BEI VERWANDTEN DES TESTOSTERONS

1962 ◽  
Vol 41 (4) ◽  
pp. 494-506 ◽  
Author(s):  
H. Langecker
Keyword(s):  
Double Bond ◽  
Ring System ◽  
Keto Group ◽  
Hydroxyl Group ◽  
Methyl Group ◽  
Structural Peculiarities ◽  
Metabolic Degradation ◽  
The Difference ◽  
Testosterone Metabolites ◽  
Derivatives Of

ABSTRACT Judging from the metabolites found in the urine, 1-methyl-androst-1-en-17β-ol-3-one (methenolone) and testosterone are metabolized in a different manner. For further clarification, other derivatives of testosterone with modifications in Ring A were investigated with regard to the oxidation of the 17-hydroxyl group. The production of urinary 17-ketosteroids decreased in the following sequence: testosterone; 1α-methyltestosterone and androstan-17β-ol-3-one; 1β-methyl-androstan-17β-ol-3-one; 2α-methyl-androstan-17β-ol-3-one and androst-1-en-17β-ol-3-one; 1α-methyl-androstan-17β-ol-3-one; 1-methyl-androsta-1,4-dien-17β-ol-3-one; 1,17α-dimethyl-androst-1-en-17β-ol-3-one and 1 -methyl-androst-1 -en-17β-ol-3-one (methenolone). The difference in metabolic degradation is also demonstrated in the fractionation of the urinary ketones. While after the administration of testosterone practically only hydrogenated 17-ketones are observed in the urine, the unchanged compound is still traceable in remarkable quantities after the administration of methenolone, along with minor quantities of the corresponding diketone. Testosterone-metabolites here are absent, whereas they represent the major substances present after the administration of androst-1-en-17β-ol-3-on. Following the administration of 1α-methyltestosterone only hydrogenated 17-ketones are detected which are still partly methylated. The 1-methyl-group and the Δ 1-double-bond seem to be responsible for the inhibition of the oxidation of methenolone in the 17-position. In addition, the hydrogenation of the double-bond and the reduction of the 3-keto-group are inhibited, obviously on account of the same structural peculiarities. The demethylation of methenolone is also inhibited. Any change in the steroid ring system forms a new substrate, thus producing new conditions for the enzymatic attack in the metabolic degradation.

scholarly journals 3-[1-(4-Bromophenyl)ethoxy]-2,2,5-trimethyl-4-phenyl-3-azahexane

2013 ◽  
Vol 69 (12) ◽  
pp. o1792-o1793
Author(s):  
Praveen Pitliya ◽  
Ray J. Butcher ◽  
A. Karim ◽  
Paul F. Hudrlik ◽  
Anne M. Hudrlik ◽  
...  
Keyword(s):  
Free Radical ◽  
Dihedral Angle ◽  
Torsion Angle ◽  
Title Compound ◽  
Ethoxy Group ◽  
Methyl Group ◽  
X Ray ◽  
Compound C ◽  
Butyl Group ◽  
Benzene Rings

The title compound, C22H30BrNO, is an alkoxyamine compound, an effective initiator in nitroxide-mediated free radical polymerization. It was prepared as a mixture of two diasteromers; the crystal for the X-ray analysis showed one of these as a pair ofR,SandS,Renantiomers. Thetert-butyl and isopropyl groups are in an almostanticonformation in the crystal [C—N—C—C torsion angle = −168.8 (1)°], and the methyl group of the ethoxy group is in an approximateantirelationship to thetert-butyl group. The dihedral angle between the phenyl and benzene rings is 33.12 (7)°. The Br atom is disordered over two positions, with occupancies of 0.9139 (16) and 0.0861 (16). In the crystal, weak C—H...Br contacts link the molecules into chains along [-110].

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