Synthesis Of 3α Research Articles

Synthesis of 3α,7α,14α‐Trihydroxy‐5β‐cholan‐24‐oic Acid: A Potential Primary Bile Acid in Vertebrates.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The Synthesis of 3α-/3β- Cholesteryl and Cholestanyl Esters and Ethers - an Assessment of their Mesogenicity

Several 3α- and 3β- esters and ethers of cholesterol and cholestanol have been prepared and their synthesis and mesogenicity is discussed.

Synthesis of 3α- and 3β-dimers from selected bile acids

New dimers of bile acids have been synthesized by linking the hydroxyl groups on C3 of the steroid skeleton with a spacer via the formation of ester or ether bonds. 3α-Dimers of lithocholic acid and cholic acid were prepared by forming ester linkages between the C3 hydroxyl group and dicarboxylic acids of different lengths, i.e., suberoyl chloride (eight carbons) and sebacoyl chloride (ten carbons). These dimers were obtained in three steps with an overall yield of about 70%. Regioselective hydrolysis of the methyl ester protecting groups on the bile acids was carried out successfully under mild alkaline conditions (aqueous lithium hydroxide with tetrahydrofuran). A 3β-dimer of lithocholic acid has also been synthesized by linking the C3 positions of two bile acids with diethylene glycol by the formation of ether linkages. The carboxylic acid groups of the bile acid dimer can be liberated by the removal of the methyl ester protecting groups.

Synthesis of 3 alpha,6 beta,7 alpha,12 beta- and 3 alpha,6 beta,7 beta,12 beta-tetrahydroxy-5 beta-cholanoic acids.

Chemical synthesis of 3 alpha,6 beta,7 alpha,12 beta- and 3 alpha,6 beta,7 beta,12 beta-tetrahydroxy-5 beta-cholan-24-oic acids is described. 3 alpha,12 beta-Dihydroxy-5 beta-chol-6-en-24-oic acid used as the starting material in the synthesis was prepared via oxidation of 3 alpha,12 alpha-dihydroxy-5 beta-chol-6-en-24-oic acid 3-hemisuccinate at C-12 followed by reduction with potassium/tertiary amyl alcohol. alpha-Epoxidation of the ester diacetate of 3 alpha,12 beta-dihydroxy-5 beta-chol-6-en-24-oic acid with m-chloroperbenzoic acid followed by cleavage of the epoxide with acetic acid and alkaline hydrolysis yielded 3 alpha,6 beta,7 alpha,12 beta-tetrahydroxy-5 beta-cholan-24-oic acid (overall yield 25%). N-Methylmorpholine-N-oxide-catalyzed osmium tetroxide oxidation of the ester diacetate of 3 alpha,12 beta-dihydroxy-5 beta-chol-6-en-24-oic acid followed by alkaline hydrolysis yielded 3 alpha,6 beta,7 beta,12 beta-tetrahydroxy-5 beta-cholan-24-oic acid (overall yield 33%). The structures of the synthesized bile acids were confirmed from their proto nuclear magnetic resonance and mass spectral fragmentation patterns.

Allylically Stannylated Cholestenes: The Synthesis of 3α-(Triphenylstannyl)cholest-4-ene, 7α-(Tributylstannyl)- and 7α-(Triphenylstannyl)cholest-5-en-3-one, and 7α-(Triphenylstannyl)-cholest-5-en-3β-ol

3α-(Triphenylstannyl)cholest-4-ene can be prepared by the reaction of triphenylstannyllithium with 3-chlorocholest-4-ene. Cholesta- 4,6-dien-3-one reacts with tributylstannyllithium, lithium bis(triphe- nylstannyl)cuprate or triphenylstannyllithium to give the corresponding 7α-(triorganostannyl)cholest-5-en-3-one, and the triphenylstannyl derivative can be reduced with lithium aluminium hydride to give 7α-(triphenylstannyl)cholest-5-en-3β-ol

Antimicrobial activity of basic cholane derivatives. X. Synthesis of 3α- and 3β-amino-5β-cholan-24-oic acids

A simple and convenient route to 3α- and 3β-amino-5β-cholan-24-oic acids was developed via Leuckart-Wallach animation reduction and subsequent acid hydrolysis. Two epimeric formylamino derivatives were produced (α and β), approximately in a 1 : 1 ratio, as determined by 13C nuclear magnetic resonance spectroscopy. The two isomers were separated by making use of their different solubilities in ethyl ether. The absolute configuration of the two amino acids was assigned by comparison with authentic reference samples.

Communication. Critiques; synthesis of 3α, 17 β-dihydroxy-5α-androstane-17-β- [formula omitted]-glucuronide

Communication. Critiques; synthesis of 3α, 17 β-dihydroxy-5α-androstane-17-β- [formula omitted]-glucuronide

The synthesis of 3α- and 3β-dihydrocadambine from secologanin

Secologanin, protected as the dimethyl acetal of its tetraacetate, had previously been dihydroxylated at the vinyl side chain with high stereoselectivity to provide the glycol (4) of the correct configuration for the synthesis of 3α- and 3β-dihydrocadambine. The glycol was converted to the cyclic acetal 5 to protect the secondary alcohol, the primary alcohol was oxidized to provide the aldehyde 6, and this was reductively coupled with tryptamine. Treatment of the coupled intermediate (8) with 90% formic acid followed by deacetylation of the glycoside led to the formation of a mixture of 3α- and 3β-dihydrocadambine (40% and 33%, respectively). The synthesis confirms the structure assigned to these alkaloids, and establishes the configuration, relative and absolute, at all centres except C-3 (where it provides no new stereochemical information).

Application of INDOR and NOE techniques to determination of the substitution pattern on an aromatic ring of erythrinan alkaloids.

The utility of the INDOR and NOE techniques for the determination of the substitution pattern on the aromatic ring of erythrinan alkaloids is demonstrated. Synthesis of 3α, 16-dimethoxyerythrinan-1 (6)-ene (III) was accomplished by a route similar to that developed by Mondon, et al.

Synthesis of 3α, 11β, 17α, 21‐tetrahydroxy‐[1−3H]‐5α‐pregnan‐20‐one, [1−3H]‐reichstein's compound C

AbstractIn order to fully understand the metabolic transformations of adrenocortical steroids, labelled 3α, 11β 17α,211‐tetrahydroxy‐5α‐pregnan‐20‐one, Reichstein's Compound C was required. Starting from hydrocortisone, the synthesis of [1−3H]‐Reichstein's Compound C has been accomplished.

Stero-bile acids and bile alcohols. XCV. Synthesis of 3-alpha, 7-alpha, 12-alpha-trihydroxy-5-beta-cholestane-24-carboxylic acid and the chemical structure of trihydroxybufosterocholenic acid isolated from toad bile.

Stero-bile acids and bile alcohols. XCV. Synthesis of 3-alpha, 7-alpha, 12-alpha-trihydroxy-5-beta-cholestane-24-carboxylic acid and the chemical structure of trihydroxybufosterocholenic acid isolated from toad bile.

3-Substituted Tropane Derivatives. II. The Synthesis of 3α- and 3β-Tropaneacetic Acids, 3-(3α-Tropanyl)propionic Acid, and Related Compounds1

3-Substituted Tropane Derivatives. II. The Synthesis of 3α- and 3β-Tropaneacetic Acids, 3-(3α-Tropanyl)propionic Acid, and Related Compounds¹