Synthesis of ecdysone. 3. On insect hormones. Syntheses of 2-beta, 3-beta, 14-alpha-trihydroxy-6-keto-delta-7-A-B-cis-steroids

The synthesis of the tetracyclic skeleton of ecdysone with correct stereochemistry and substitution is described. 22,25-Didehydroxy-ecdysone and methyl (20S)-2β,3β-dihydroxy-6-oxo-5β-pregn-7-ene-20-carboxylate have been prepared. The latter is a key intermediate in the synthesis of ecdysone.     

Steroid total synthesis. 3. 9 , 10 -testosterone

The total synthesis of 9β, 10α-testosterone via a BCD-tricyclic intermediate is described. The latter compound – 17β-hydroxy-des-A-androst-9-en-5-one – was obtained in optically active form by our previously reported scheme, using an efficient resolution step early in the synthesis. New results regarding the asymmetric induction step are also discussed.     

Stereospezifische Synthese von 6β,7β-Methylen-20-spirox-4-en-3,21-dion (Prorenon). Über Steroide. 235. Mitteilung

Stereospecific synthesis of 6β,7β-methylene-20-spirox-4-ene-3,21-dione A stereospecific synthesis of the highly active 6β,7β-methylene-20-spirolactone 4 (Prorenone) is described.     

Die Struktur der Drevogenine. 2. Mitteilung Struktur von Drevogenin P. Glykoside und Aglykone, 278. Mitteilung

Drevogenin A was converted in several steps (acetylation, hydrogenation, dehydration, hydrogenation, the haloform reaction and energetic alkaline hydrolysis) into 3β, 11α, 12β-trihydroxy-5α-etianic acid, which could be characterised by its crystalline methyl ester ( 15 ) and its tri-O-acetyl methyl ester ( 16 ). The same acid was obtained by partial synthesis starting from hecogenin. Taking into consideration earlier results [1], the structure of drevogenin P is proved to be 3β, 11α, 12β, 14β-tetrahydroxy-20-oxo-Δ⁵-pregnene ( 7 ). Energetic hydrolysis of dihydro-3-O-acetyldrevogenin A gave a mixture of 17αH- and 17βH-desacyl-kondurangogenin A, which were obtained in crystalline form after separation by chromatography. The only difference between the basic structures of the drevogenins and kondurangogenin A is the presence of a double bond in the 5-position in the former.     

Zur Synthese des Ecdysons. II. Mitteilung über Insektenhormone Synthesen von 2β, 3β-Dihydroxy-6-keto-A|B-cis-Steroiden

Experiments towards a synthesis of ecdysone ( 1 ) ([22R]-2β, 3β, 14, 22, 25-pentahydroxy-5β, 14α-cholest-7-en-6-one) have led to 2β, 3β-dihydroxy-6-keto-5α-steroids. These could be epimerized to the corresponding 5β-series. The proposed configurational assignments are supported by physical data and chemical correlation.     

Alloglaucotoxigenin,Strukturbestimmung Glykoside und Aglykone, 280. Mitteilung

The structure of alloglaucotoxigenin is shown to be that of 3β, 14β, 15β-trihydroxy-19-oxo-5α-carda-20:22-enolide (IV) in the following way: The 19-oxo group could be eliminated by reduction of the corresponding mercaptal. The structure of the resulting 3β, 14β, 15β-trihydroxy-5α-carda-20:22-enolide, obtained in the acetylated form, was established through degradation and through partial synthesis by treatment of Δ¹⁴-anhydro-uzarigenin (XIII) with osmium tetroxide. The isomeric 3β,14α, 15α-trihydroxy-cardenolide was also formed in large quantities. The substance XI showed in its optical rotatory dispersion curve a positive, and substance XIV a negative COTTON effect.     

Aminonucleosides. IV. (3-Amino-3-desoxyerythrofuranosyl)-9-adenine

The synthesis of 9-(3-amino-3-deoxy-β-L-(and D)-erythrofuranosyl)-adenine is described. This compound is a close analog of the aminonucleoside of puromycin.     

Synthese eines homologen steroidischen 17β-Pyrrolinons Partialsynthetische Versuche in der Reihe der Herzgifte, 9. Mitteilung

Synthesis of a homologous steroidal 17β-pyrrolinone. We describe the synthesis of 4′-[(3β-Hydroxy-androst-5-en-17β-yl)methyl]-3′-pyrrolin-2′-one ( 15 ) starting from 3β-acetoxy-23-diazo-21,24-dinorchol-6-en-22-one ( 1 ).     

Steroids and sex hormones. 242. Preparation of 14-beta-hydroxy-2-keto-delta-16-steroids: a new highly productive access to 33-O-methyl-17-alpha, 20-xi-tetrahydrobatrachotoxinin A

A novel method for the reductive epoxide opening in a 14β, 15β-epoxy-20-oxo-Δ¹⁶-pregnene 4 affords an almost quantitative yield of the 14β-hydroxy-20-oxo-Δ¹⁶-pregnene 5. This leads to a considerable improvement of the formerly published synthesis of 3-O-methyl 17 α, 20ξ-tetrahydrobatrachotoxinin A ( 2 ) [3].     

Steroids and sex hormones. The synthesis of 1-beta, 4-beta-oxido-3-aza-17-beta-hydroxy-A-homo-5-alpha-androstane

A sterically controlled transformation of 3-oxo-17β-acetoxy-Δ^1?-α-androstene ( 2 ) into 1β,4β-oxido-3-aza-17β-hydroxy-A-homo-5α-androstane ( 16 ) is described. With the exception of two conversions [ 14 → 15 (60%); 15 → 16 (50%)], the yields of the remaining seven steps are higher than 75% each. The reaction sequence will serve as a model for an analogous partial synthesis of samandarine ( 1 ).     

Totalsynthese von Steroiden. 1. Mitteilung. rac-17β-Hydroxydes-A-androst-9-en-5-on

In connection with earlier work on the synthesis of 9β, 10α-steroids, a new and practical synthesis of rac-17α-hydroxy-des-A-androst-9-en-5-one ( 19 ) has been developed, based on a novel stereoselective condensation of 7-hydroxy-1-nonen-3-one ( 3 ) with 2-methyl-cyclopentane-1, 3-dione ( 9 ) and subsequent transformations of the resulting tricyclic diene ether 12 .     

Reissert compound studies. XLII. Synthesis and reactions of the 3,4-dihydro-β-carboline reissert compound and observations on α, β, and γ-carbolines

3,4-Dihydro-β-carboline and benzo[α]-γ-carboline yielded Reissert compounds. The 3,4-dihydro-β-carboline Reissert compound, through its acid- and base-promoted reactions, was found to be a very useful intermediate in the synthesis of several β-carboline derivatives including tetracyclic compounds. Reaction of the 3,4-dihydro-β-carboline Reissert compound with dichlorodicyanobenzoquinone (DDQ) resulted in the formation of l-cyano-β-carboline thereby providing the first example of an oxidation of a Reissert compound with DDQ. α-, β- and γ-Carbolines failed to form Reissert compounds under a wide variety of conditions. 7-Azaindole also failed to yield a Reissert compound.     

Alcaloïdes stéroïdiques—CLXXVIII: synthèse d'azides tertiaires—VIII: Synthèse d'azido et d'amino-14β cardénolides

The use of hydrazoic acid in the presence of BF₃-etherate allows the synthesis of the potentially interesting 14β-amino cardenolides. The 17βH configuration allows a quantitative yield of the 14β-azido cordenolide, but by this method, the 17αH configuration does not. However, the synthesis of the 14β-azido cardenolide of 17αH configuration can be achieved by the elaboration of a 14β-azido 17αH-pregnane.     

Synthesis of 19-hydroxysteroids I. New synthesis of 19-hydroxytestosterone

For obtaining 19-hydroxytestosterone from dehydroepiandrosterone a new scheme of synthesis has been developed the key stages of which are the reduction of the 17-keto group to a 17-alcohol, the functionalization of the 19-methyl group via the bromohydrin with the formation of a 6β,19-epoxide, the selective hydrolysis of the free β-acetoxy group, the conversion of the 3β-hydroxy-5α-bromo derivative into the Δ⁴-3-ketone, and the reductive cleavage of the 6β,19-epoxide ring.     

Stereocontrolled Conversion of 3-Unsubstituted Isoxazole Compounds into Z-β-Siloxyacrylonitriles. A New Method for the Regioselective Synthesis of β-Enaminoketones

The stereoselective synthesis of Z-β-siloxyacrylonitriles via base-induced ring cleavage of isoxazole precursors is described. Z-β-siloxyacrylonitriles react with organolithium compounds to give high yields of β-enaminoketones 1.     

Model studies towards the synthesis of 2-β-hydroxymethyl penicillin N

The synthesis of 2-β-hydroxymethyl penicillin V sulfoxide is described as a model study towards the synthesis of 2-β-hydroxymethyl penicillin N.     

Synthetic quinine,analogs. V. Quinolinemethanols related to desvinylquinine

Aldol condensation of quinolinecarboxaldehydes with 3-quinuelidinone followed by acid-catalyzed hydration of the resulting α,β-unsalurated ketones provides a short and versatile synthesis of desvinylquinine derivatives. A novel rearrangement of 2-(9-phenanthrylmethylene)-3-quinuclidinyl earbinols leading to dibenzoindole derivatives is described.     

A novel sulfur containing C35 hopanoid in sediments.

A C₃₅ pentacyclic triterpenoid of the hopane series containing a thiophene ring, 30-(2′-methylene thienyl)-17β(H),21β(H)-hopane 1, has been confirmed in immature sediments by synthesis, suggesting incorporation of bacterial sulfur into geological organic matter at early stages of sedimentation.     

Synthesis of heterosteroids. First synthesis of oxa steroid from cholic acid

We wish to report here a new and efficient partial synthesis of 3-oxa-5β-steroid, the first oxa steroid synthesized from cholic acid.     

14-methyl steroids. Part 3. Synthesis of (±)-14α-methyl-9β-estradiol and related 14α-methyl-19-norsteroids

Catalytic hydrogenation of a totally synthetic mixture of (±)-3-methoxy-14-methyl-14α-estra-1,3,5( 10), 9(11)-tetraen-17-one(1) and the corresponding 1,3,5(10),8-tetraen-17-one (2) gives a mixture of 14α-methyl-8β,9β-, -8α,9α-, and -8β,9α-estrones, which is converted into the 17β-hydroxy-mixtures. t-Butylation gives a separable mixture of the three isomers, of which (±)-17β-t-butoxy-3 methoxy-14-methyl-9β,14α-estra-1,3,5(10)-triene(6) is the major component. The corresponding 14α-methylestradiols are prepared. A practical synthesis of (±)-14-methyl-14α-estra-1,3,5(10), 6,8-pentaene-3,17β-diol(25) is described, and it is shown that DDQ dehydrogenation of 1,3,5(10),9(11)-tetraenes in this series leads exclusively to the corresponding 1,3,5(10),6,8,11-hexaenes, whereas that of 1,3,5(10),8-tetraenes gives only 1,3,5(10),6,8-pentaenes.