Microbial hydroxylation of steroids. 6. Hydroxylation of C-6-substituted androst-4-ene-3,17-diones by Rhizopusarrhizus ATCC 11145

1979 ◽  
Vol 57 (13) ◽  
pp. 1585-1587 ◽  
Author(s):  
Herbert L. Holland ◽  
Peter R. P. Diakow
Keyword(s):  
Microbial Hydroxylation ◽  
Enol Acetates

The products arising from the incubations of C-6α and C-6β chloro-, fluoro-, and methyl-substituted Δ4-3-keto steroids with the C-6β hydroxylating fungus Rhizopusarrhizus ATCC 11145 have been identified, and their formation rationalised in terms of Δ3,5 enolic intermediates. The incubations of C-6 chloro and methyl Δ3,5 enol acetates with R. arrhizus, and the oxidations by m-chloroperoxybenzoic acid of the corresponding enol ethyl ethers have also been described. The relevance of the results so obtained to the mechanism of C-6β hydroxylation of Δ4-3-keto steroids by R. arrhizus is discussed.

Microbial hydroxylation of steroidal Δ3,5 enol acetates

1975 ◽  
Vol 16 (44) ◽  
pp. 3787-3788 ◽  
Author(s):  
Herbert L. Holland ◽  
Barbara J. Auret
Keyword(s):  
Microbial Hydroxylation ◽  
Enol Acetates

Electrochemical Synthesis of Fluorinated Ketones from Enol Acetates and Sodium Perfluoroalkyl Sulfinates

2021 ◽  
Author(s):  
Vera A. Vil’ ◽  
Valentina M. Merkulova ◽  
Alexey I. Ilovaisky ◽  
Stanislav A. Paveliev ◽  
Gennady I. Nikishin ◽  
...  
Keyword(s):  
Electrochemical Synthesis ◽  
Enol Acetates

The photoaddition of 1,3-diketonatoboron difluorides with benzene derivatives

1991 ◽  
Vol 69 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Yuan L. Chow ◽  
Xinxin Ouyang
Keyword(s):  
Crystallographic Analysis ◽  
Secondary Oxidation ◽  
Enol Ethers ◽  
X Ray ◽  
Thermal Reactions ◽  
Secondary Reactions ◽  
Enol Acetates ◽  
Orthogonal Orientation ◽  
Acid Catalyzed ◽  
Boron Difluoride

The boron difluoride complexes of 2-acetylcyclohexanone, 2-acetylcyclopentanone, and acetylacetone (abbreviated as ACHBF2, ACPBF2, and AABF2) were irradiated in the presence of benzene to give the 1:1 adducts as the primary photoadducts; for certain BF2 complexes, toluene, chlorobenzene, benzonitrile, and methyl benzoate were also used as substrates. The 1,5-diketone photoadducts were assumed to form by a [2+2] photocycloaddition followed by cyclobutane opening and hydrolysis to give 1,2 adducts. They undergo a variety of secondary thermal reactions, probably acid catalyzed, to give enol ethers, enol acetates, acetophenones, and ketonylacetophenones. The efficiency of these secondary reactions determines the final products. Photoaddition with a monosubstituted benzene preferentially occurs at the 3,4 bond without regioselectivity. Under oxygen, ACHBF2 photolytically reacts with benzene to give a secondary oxidation product of a 10-membered cyclic alkylphe-none, which is proven by X-ray crystallographic analysis to have the benzene ring and carbonyl group in orthogonal orientation. It is shown that the singlet excited state ACHBF2 initiates the photoaddition, probably through the formation of the benzene exciplex, which could be detected by its emission. While the Stern–Volmer rates are small, the quantum yield of photoaddition products is as high as 0.12–0.19 under limiting conditions. Key words: [2+2] photocycloaddition, non-planar alkanophenone, macrocyclic alkanophenone, boron difluoride complexes, photoaddition to benzenes.

Production of 16β-(acetoxy)acetoxy derivatives by reaction of 17-keto steroid enol acetates with lead (IV) acetate

Steroids ◽  
2001 ◽  
Vol 66 (10) ◽  
pp. 743-748 ◽  
Author(s):  
M Numazawa
Keyword(s):  
Enol Acetates

Microbial hydroxylation of acronycine

1974 ◽  
Vol 17 (6) ◽  
pp. 653-654 ◽  
Author(s):  
D. R. Brannon ◽  
D. R. Horton ◽  
Gordon H. Svoboda
Keyword(s):  
Microbial Hydroxylation

ChemInform Abstract: Microbial Hydroxylation of Some Steroids by Aspergillus wentii MRC 200316.

ChemInform ◽  
2011 ◽  
Vol 42 (11) ◽  
pp. no-no
Author(s):  
Kudret Yildirim
Keyword(s):  
Microbial Hydroxylation ◽  
Aspergillus Wentii

scholarly journals Microbial hydroxylation of progesterone withAcremonium strictum

2003 ◽  
Vol 222 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Mohammad Ali Faramarzi ◽  
Mojtaba Tabatabaei Yazdi ◽  
Mohsen Amini ◽  
Gholamreza Zarrini ◽  
Abbas Shafiee
Keyword(s):  
Microbial Hydroxylation

The Mechanism of the Microbial Hydroxylation of Steroids. Part 2. Hydroxylation of a Δ4-3-Ketosteroid Analog by Rhizopus arrhizus ATCC 11145

1975 ◽  
Vol 53 (14) ◽  
pp. 2041-2044 ◽  
Author(s):  
Herbert L. Holland ◽  
Barbara J. Auret
Keyword(s):  
Transition State ◽  
Rhizopus Arrhizus ◽  
Microbial Hydroxylation ◽  
Microbial C

The Δ4-3-ketosteroid analog (± )-4a-methyl-4,4a,5,6,7,8-hexahydro-2(3H) naphthalenone (1) is hydroxylated at both C-8α and C-8β by Rhizopusarrhizus ATCC 11145. The ratio of C-8α to C-8β hydroxylation is compared with that obtained from the peracid oxidation of 2-ethoxy-4a-methyl-3,4,4a,5,6,7-hexahydronaphthalene (4) and a mechanism is proposed for both microbial and chemical hydroxylation in which the stereochemistry of the product is transition state controlled. The significance of this to the mechanism of microbial C-6β hydroxylation of Δ4-3-ketosteroids is discussed.

Catalyst‐Free and Oxidant‐Free Cascade Difluoroalkylation and Controllable C−F Bond Activation of Aryl Enol Acetates for the Synthesis of β‐Fluoroenones and β‐Enaminones

2021 ◽  
Author(s):  
Wenshuang Li ◽  
Ruyan Liu ◽  
Ruonan Li ◽  
Shihaozhi Wang ◽  
Dianjun Li ◽  
...  
Keyword(s):  
Bond Activation ◽  
Catalyst Free ◽  
Enol Acetates
Sign in / Sign up

Export Citation Format

Share Document