E. G. Cherepanova

13C NMR spectra of 17-substituted epimeric 17? and 17?-ethynylandrostenes and their hexacarbonyldicobalt complexes

Abstract13C NMR spectra of epimeric 17α-R-substituted 17β-ethynylandrostenes (R = H, OH, OAc, OMe, NCS) and 17β-R-substituted 17α-ethynylandrostenes (R = H, OH, OAc, OMe), and their hexacarbonyldicobalt complexes, as well as of Δ16-17-ethynylandrostenes and their hexacarbonyldicobalt complexes have been studied. Stereochemical dependence of C(12), C(14), C(18), C(20) and C(21) chemical shifts on the configuration of the substituents at C(17) has been demonstrated. The effect of Co-complexation on the spectral characteristics of Co-coordinated 17-ethynylandrostenes in both Stereochemical series has been investigated.

Transformed steroids. Communication 140. 17α-aza-D-homoandrostanes — Their properties and transformations

ConclusionsThe reaction of 17-acetylamino-17α-aza-D-homoandrostene with mesitylenesulfonylhydroxyl-amine proceeds with the formation of steroid amidrazones.

Transformed steroids 176. Reaction of Δ5-3β-substituted 16α,17α-cyclohexanopregnen-20-ones with thiols: synthesis of 3-mono- and 3,5-bis-sulfur-containing steroids

Conclusions1.The reaction of Δ5-3β-substituted pentaranes with ethanedithiol and thiophenol in the presence of BF3 etherate results in the formation of a mixture of 3-mono- and 3, 5-bisalkylthio products.2.A convenient method for the introduction of a mercapto substituent into the 3β-position of the steroid molecule was developed.

13C NMR spectra and structure of 16α, 17α-cyclohexanopregnanes with sulfur-containing substituents in rings A and B

Conclusions1.The high-resolution13C NMR spectra were analyzed for 16α, 17α-cyclohexanopregnanes substituted in rings A and B by SR (R=Ph, CH2CH2SH) and S(O)Ph groups. These spectra were used to determine the position of the double bond (Δ4 or Δ5) and the position and orientation of the 3α-SR, 3β-SR, 5α-SR, and 3β-S(O)Ph substituents.2.The α-, gb-, γ-, and δ-effects of the SR (R=Ph, CH2CH2SH) and S(O)Ph substituents on the chemical shifts of the carbon atoms of the steroid skeleton were determined and analyzed. A diastereotopic effect of the S(O)Ph group on the chemical shifts of the carbon atoms of rings A and B was discovered.

Transformed steroids. 159. D-D′-homoannelation of 20-epimeric alcohols in the pregna-D6′-pentarane series

ConclusionsA D-D′-homoannelation of 20β- and 20α-epimeric alcohols of the pregna-D6′-pentarane series with rupture of the C16-C17 and C17-C21 bonds, respectively, has been discovered.

Transformed steroids. Communication 148. 1,3-Cycloaddition of diazomethane and diazoacetate to Δ15-17-ketoandrostane at normal and high pressures

Conclusions1,3-Cycloaddition of diazomethane and ethyl diazoacetate to Δ15-17-ketoandrostane proceeds regio- and stereospecifically from the β-region of the steroid molecule, The pyrazolinoandrostanes obtained were converted into the corresponding 15β,16β-cyclopropane derivatives.

Structural direction of hydrogenation of some Δ4(5)-6-ketopyranosteroids

ConclusionsThe structural direction of the hydrogenation of steroidal 3β-acetoxy-Δ4-6-ketones depends on the substitution at C17, and due to this it becomes possible to approach the 5αH analogs from the 5α-hydroxy-6-keto-17-desoxysteroids.

13C NMR spectra and stereoisomerism in series of androstano-and estrano-D′-pentaranes

ConclusionsThe stereoisomerism in series of androstano- and estrano-D′-pentaranes in solution has been investigated by13C NMR. The orientation of the D′ ring in the 15α,16α-, 15β,16β-, and 15α,16β-isomers relative to the steroid skeleton, as well as the “boat” conformation of the D′ ring, were determined from the13C chemical shifts.

Transformed stroids: Communication 137. Synthesis and stereochemistry of steroid 23-methoxytetrahydropyranols

ConclusionsSteroid 22-desoxypyranoses, isomeric with respect to C23 were synthesized. The stereochemistry of their substituents was confirmed by1H and13C NMR spectroscopy.

13C NMR spectra and structure of azasteroids with an N-acylamidine fragment in the D ring

Conclusions1.The13C and1H NMR spectra of isomeric steroids of the 17-aza and 17a-aza series with an amidine fragment in the D ring have been investigated.2.The13C chemical shifts make it possible to identify isomeric steroids and to determine the position of the double bond in the amidine fragment. It has been shown that compounds with a single substitution in the amidine fragment exist in the acylimine form, while the disubstituted compounds exist in acyl- and diacylamide forms. The acylimine form forms a cyclic intramolecular hydrogen bond of the NO=O...HN type.3.The γ effects of an =NR group in the D ring in an eclipsed conformation are similar to the γ effect of the oxygen atom in a carbonyl group in D-homoandrostanes.4.The rotation of a 17a-diacylamide group, unlike that of a 17-acylamide group, is hindered.