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1.
Ya. A. Gur’eva O. A. Zalevskaya L. L. Frolova I. N. Alekseev P. A. Slepukhin A. V. Kuchin 《Russian Journal of General Chemistry》2014,84(1):137-142
Oximes of cis-caran-4-one, 3α- and 3β-hydroxycaran-4-ones, cis-verbanone, menthone, and 2β-hydroxybornan-3-one have been synthesized. The obtained oximes react with lithium tetrachloropalladate to give new chiral palladium complexes containing mono-or bidentate oxime ligands. 相似文献
2.
Successive treatment of 5α-cholestan-3-one ( 1 ) with O2 under basic conditions and then NaBH4 led to 5α-3-oxa-cholestan-2-one ( 5 ). Analogous reactions with 5β-cholestan-3-one ( 6 ) yielded 5α-4-oxa-cholestan-3-one ( 7 ) and 5 ξ-3-oxa-cholestan-4-one ( 8 ). 4-Cholesten-2-one ( 10 ), which was prepared starting from 4-cholesten-3-one, was isomerized by methanolic KOH to give a mixture of 5α-cholest-3-en-2-one ( 11 ) and 5β-cholest-3-en-2-one ( 12 ). 5β-Cholestane-2,3-dione ( 17 ) was synthesized from 4β-bromo-5β-cholestan-3-one ( 13 ). Ozonolysis of the dione 17 and subsequent NaBH4 reduction of the oxidation product gave both 5β-2-oxa-cholestan-3-one ( 18 ) and 5β-3-oxa-cholestan-2-one ( 19 ). 相似文献
3.
Treatment of A-nor-Δ3(5)-cholestene-2-one ( 1 ) with alkaline hydrogen peroxide gave 3β,5-epoxy-A-nor-cholestane-2-one ( 2 ) and the epoxylactone 3 (BAEYER -VILLIGER reaction). LiAlH4-reduction of 2 yielded A-nor-5β-cholestane-2β,5-diol( 4 ) (main product) and A-nor-5β-cholestane-2α,5-diol ( 5 ). LiAlH4-reduction of 1 led mainly to A-nor-Δ3(5)-cholestene-2α-ol ( 8 ). Catalytic hydrogenation of 8 gave the known A-nor-5α-cholestane-2α-01 ( 10 ), A-nor-5β-cholestane-2α-01 ( 11 ) (main product), A-nor-5β-cholestane ( 9 ) and A-nor-5β-cholestane-2-one ( 12 ). By LiAlH4-reduction of the ketones 12 and 13 the two additional alcohols 14 and 15 were obtained. 相似文献
4.
The reaction of 7-dehydrocholesterylbenzoate with the title reagent at a temperature of ?20° yields 50% 1, 3β-benzoyloxy-5α,14α-diazidocholest-7-en-6-one, and 25% 2, 3β-benzoyloxy-5α- azido-cholest-7-en-6-one. Under the same conditions 3,5-cholestadiene yields 3α,6β-diazidocholest-4- ene (40%; 3) and 6β-azido-cholest-4-en-3-one (6%; 4). The structure elucidation of the compounds 1–4 is supported by spectroscopy. 相似文献
5.
《Tetrahedron》1987,43(17):3987-3995
In the DMSO/NaHCO3 system, 16α-aminomethyl-, 16α-benzylaminomethyl- and substituted benzylaminomethyl-3-methoxy-17β-tosyloxyestra-1,3, 5(10)-triene (3, 5a-k) do not undergo oxidation, but form a tetrahydrooxa-zin-2-one ring (7, 8a-k) via neighboring group participation. Under similar conditions, 16β-aminomethyl-3-methoxy-17β-tosylestra-1,3,5(10)-triene (4) decomposes into 16-methylene-3-methoxyestra-l,3,5(10)-trien-17-one (12). 相似文献
6.
A synthesis of 11-homo-aldosterone acetate (1a) is described. 3β-Acetoxy-11-methylene-5α,25D-spirostan (3) was converted in 4 steps into 3β-acetoxy-11β-acetoxymethyl-5α-pregnan-20-one (9, Chart I), which was photocyclized to 20a, saponified regioselectively, and oxidized to 3-oxo-11β-acetoxymethyl-18,20-cyclopregnan-20α-ol-3-one (22, Chart II). Introduction of the 1,4-diene in 22 followed by a selective reduction of the 1-ene afforded 11β-acetoxymethyl-18,20-cyclopregn-4-en-20α-ol-3-one (26). Finally, the 18,20-cyclo ring of 26 was manipulated through 30, 31, 32, 33 to produce 1a. The bulky 11β-acetoxymethyl group distorted the steroid molecule to such an extent that the routine photochemical functionalization of the angular Me-18 via a nitrite or a hypoiodite became inoperative, and routine procedures for introduction of a 4-ene into 5α-3-one via a 1,4-dien-3-one were unsuccessful. Two new methods for the introduction of a 4-ene into steroidal 5α-3-ones were investigated using 5α-cholestanone and 5α-dihydrotestosterone as models. The first route, which was applicable to the synthesis of 1a, was the stepwise introduction of a 1-ene and a 4-ene utilizing Sharpless's acidic phenylselenyl chloride procedure, followed by a selective reduction of the 1-ene. The second route, which appeared equally promising, was protection of the C-2 site with N-methylanilinomethylene followed by introduction of the 4-ene and subsequent deprotection of the C-2. 相似文献
7.
Athanassios Tzikas Christoph Tamm Arthur Boller Andor Fürst 《Helvetica chimica acta》1976,59(5):1850-1866
20, 21-Aziridine Steroids: Reaction of Derivatives of the Oximes of 5-Pregnen-20-one, 9β, 10α-5-Pregnen-20-one and 9β, 10α-5,7-Pregnadiene-20-one with Lithium Aluminium Hydride, and of 3β-Hydroxy-5-pregnen-20-one Oxime with Grignard Reagents. Reduction of 3β-hydroxy-5-pregnen-20-one oxime ( 2 ) with LiAlH4 in tetrahydrofuran yielded 20α-amino-5-pregnen-3β-ol ( 1 ), 20β-amino-5-pregnen-3β-ol ( 3 ), 20β, 21-imino-5-pregnen-3β-ol ( 6 ) and 20β, 21-imino-5-pregnen-3β-ol ( 9 ). The aziridines 6 and 9 were separated via the acetyl derivatives 7 and 10 . The reaction of 6 and 9 with CS2 gave 5-(3β-hydroxy-5-androsten-17β-yl)-thiazolidine-2-thione ( 8 ). Treatment of the 20-oximes 12 and 15 of the corresponding 9β,10α(retro)-pregnane derivatives with LiAlH4 gave the aziridines 13 and 16 , respectively. Their deamination led to the diene 14 and triene 17 , respectively. Reduction of isobutyl methyl ketone-oxime with LiAlH4 in tetrahydrofuran yielded 2-amino-4-methyl-pentane ( 19 ) as main product, 1, 2-imino-4-methyl-pentane ( 22 ) as second product and the epimeric 2,3-imino-4-methyl-pentanes 20 and 21 as minor products. – 3β-Hydroxy-5-pregnen-20-one oxime ( 2 ) was transformed by methylmagnesium iodide in toluene to 20α, 21-imino-20-methyl-5-pregnen-3β-ol ( 23 ) and 20β, 21-imino-20-methyl-5-pregnen-3β-ol ( 26 ). Acetylation of these aziridines was accompanied by elimination reactions leading to 3β-acetoxy-20-methylidene-21-N-acetylamino-5-pregnene ( 30 ) and 3β-acetoxy-20-methyl-21-N-acetylamino-5,17-pregnadiene ( 32 ). The reaction of oxime 2 with ethylmagnesium bromide in toluene gave 20α, 21-imino-20-ethyl-5-pregnen-3β-ol ( 24 ) and 20α,21-imino-20-ethyl-5-pregnen-3β-ol ( 27 ). Acetylation of 24 and 27 led to 3β-acetoxy-20-ethylidene-21-N-acetylamino-5-pregnene ( 31 ), 3β-acetoxy-20-ethyl-21-N-acetylamino-5,17-pregnadiene 33 and 3β, 20-diacetoxy-20-ethyl-21-N-acetylamino-5-pregnene ( 37 ). With phenylmagnesium bromide in toluene the oxime 2 was transformed to 20β, 21-imino-20-phenyl-5-pregnen-3β-ol ( 25 ) and 20β,21-imino-20-phenyl-5-pregnen-3β-ol ( 28 ). Acetylation of 25 and 28 yielded 3β-acetoxy-20-phenyl-21-N-acetylamino-5, 17-pregnadiene ( 34 ) and 3β,20-diacetoxy-20-phenyl-21-N-acetylamino-5-pregnene ( 39 ). LiAlH4-reduction of 39 gave 3β, 20-dihydroxy-20-phenyl-21-N-ethylamino-5-pregnene ( 41 ). – The 20, 21-aziridines are stable to LiAlH4. Consequently they are no intermediates in the formation of the 20-amino derivatives obtained from the oxime 2 . 相似文献
8.
Jean Guillaumel Pierre Demerseman Jean-Marc Clavel Ren Royer 《Journal of heterocyclic chemistry》1980,17(7):1531-1536
When treated with acetyl chloride and ferric chloride in methylene chloride, at 0°, monosubstituted β-nitrostyrene derivatives such as 2,3 or 4-methyl, -chloro or -fluoro and 3-nitro-β-nitrostyrenes cyclize into the new corresponding 3-chloro-1,3-dihydro-2H-indol-2-one. Reaction with other metal chlorides such as aluminum chloride and titanium tetrachloride does not lead to these heterocyclic derivatives but only produces N-acetyl-N-hydroxy-α-chlorobenzeneacetamides and/or N-(acetyloxy)-α-chlorobenzeneethanimidoyl chlorides. 相似文献
9.
《Tetrahedron letters》2005,46(16):2771-2774
Treatment of 3β-acetoxy-5-bromo-6β,19-epoxy-5α-androstan-17-one with Ac2O and BF3·OEt2, produced the cleavage of the epoxy moiety and migration of the bromine atom to afford 3β,19-diacetoxy-6α-bromo-5-hydroxy-5β-androst-17-one in high yield. 相似文献
10.
The BF3-catalysed rearrangement of 6β-acetoxy-3α,5-epoxy-5α-cholestane gave the 3α,5β-diol, the 3α,10α-epoxide, and the 2α,5α-epoxide, and the product of solvolysis of 3β-tosyloxy-5β-cholestan-5-ol-6-one was identified as 3α,5-epoxy-A-homo-B-nor-5α-cholestan-4a-one. 相似文献
11.
5-p-Chlorophenyl-6,6-dimethyl-5,6-dihydro-3H-furano[2,3-d]pyrimidine-4-one is readily converted to 4,6-dichloro-5-β-β-dimethyl-α- (p-chlorostyryl)pyrimidine by warming in phosphorus oxychloride and acetic acid, behavior which is in strong contrast to that of the analogous 5-phenyl derivative. The reaction provides a convenient source of 4-amino-6-chloro-5β,β-dimethyl-α- (p-chlorostyryl)pyrimidines and 4,6-diamino-5-β,β-dimethyl-α- (p-chlorostyryl)pyrimidines, compounds of potential biological interest. 相似文献
12.
The base-catalysed rearrangement of 3β, 16α-dihydroxy-5α-androstan-17-one diacetate ( 1 ) in (D6)benzene/ CD3OD to 3β, 17β-dihydroxy-5α-androstan-16-one ( 3 ) is followed by 13C-NMR spectroscopy. By the same procedure, it is determined that in (D6)benzene/CD3OD, but under acid catalysis, 1 does not rearrange to 3 but yields the intermediate product 3β, 16α-dihydroxy-5α -androstan-17-one 17α -methyl hemiacetal ( 5 ). 相似文献
13.
Anu J Airaksinen Jarkko LipsonenMarkku Ahlgren Pirjo VainiotaloKim A Bergström Reino LaatikainenJouko Vepsäläinen 《Tetrahedron》2003,59(3):377-383
Reduction of 6/7-carboethoxy-3-phenyltrop-3-en-2-ones with H2/Pd/C and NaBH4 was studied in order to find a stereoselective route to the corresponding 3-phenyltropan-2-ones and 2α/2β-hydroxy-3-phenyltropanes. The 6/7-exo-carboethoxy-3-phenyltrop-3-en-2-ones were selectively reduced by Pd/C to 3β-phenyltropan-2-ones and 2α-hydroxy-3β-phenyltropanes. The corresponding 2β-hydroxy-3β-phenyl analogues were synthesized using NaBH4, with a yield of 40%. Reduction of 6-endo-carboethoxy-3-phenyltrop-3-en-2-one yielded several products. The corresponding 7-endo-substituted analogue was selectively reduced with both Pd/C and NaBH4 to 7-endo-carboethoxy-3β-phenyltropin-2-one. Analysis of stereochemically important 1H NMR spectroscopy parameters was performed for all the products and used for conformational analysis in solution. X-ray analysis was performed for selected compounds. 相似文献
14.
Recently, β-chloro-α,β-unsaturated carbonyl compounds have become increasingly useful as intermediates in organic synthesis. For example, reactions involving a number of different cyclic β-chloro-α,β-unsaturated ketones with a variety of reagents (a malonate anion2, the anion of the dithiolane derivative of ethyl glyoxalate3, zinc-silver couple in methanol4, dimethylsulfoxonium methylide5,6) have produced a series of structurally diverse and potentially fruitful synthetic intermediates. The second-mentioned reagent has also been successfully reacted with a β-chloro-α,β-unsaturated ester3. 相似文献
15.
3-Methoxy-5-chloro-6-methyl-2(H)-1,4-oxazin-2-one 4, 3-methoxy-5-chloro-6-phenyl-2(H)-1,4-oxazin-2-one 5, 3-phenylsulfenyl-5-chloro-6-methyl-2(H)-1,4-oxazin-2-one 6, and 3-phenylsulfenyl-5-chloro-6-phenyl-2(H)-1,4-oxazin-2-one 7, are ambident dienes and undergo Diels-Alder cycloadditions with electron neutral, rich and deficient dienophiles. 相似文献
16.
The fruit body of Lasiosphaera fenzlii was found to show cytotoxicity on cancer cells during a preliminary screening. Repeated column chromatography of the fungal methanol extract resulted in the isolation of six compounds identified as 5α,8α-epidioxy-ergosta-6,22-dien-3β-ol (1), 5α,8α-epidioxy-ergosta-6,9(11),22-trien-3β-ol (2), 5α-ergosta-7,22-dien-3β-ol (3), 5α-ergosta-7,22-dien-3-one (4), ergosta-7,22-dien-3β,5α,6β-triol (5) and 6-dihydroxy-2,3-dihydro-1H-isoindol-1-one (6). The two peroxide compounds, 1 and 2, showed cytotoxic activity and compound 1 was selectively cytotoxic to cancer cells. Furthermore, compound 1 synergised the cytotoxicity of paclitaxel on Hela cells by increasing intracellular accumulation of paclitaxel in cancer cells but not in normal cells. 相似文献
17.
Tordanone, a Twice Bent Steroid Structure with Ring A/B β-cis(5β)- and Ring B/C α-cis(8α)-Fused The 3β, 14α, 25-trihydroxy-5β, 8α-cholestan-6-one ( = tordanone; 4 ) has been prepared by stereospecific hydrogenation of 3β, 14α, 25-trihydroxy-5β-cholesta-7,22ξ-dien-6-one ( 5 ). This is the first stereospecific synthesis of a B/C cis-fused steroid belonging to the 5β, 8α -cholestane group with a H-atom at positions 5β (A/B cis-fused) and 8α. The resulting twice bent structure shows a particularly strong steric hindrance of the β-face where CH3(18) at the C/D ring junction and Hβ? C(7) of the B ring are very close to each other. Structural features and mechanistic aspects of the hydrogenation are discussed. 相似文献
18.
Jessica D. Townsend Wayne Kelley Jr. Kelly L. Rose Deborah A. Schady Jennifer R. Downs Heather A. Greer 《合成通讯》2013,43(12):2175-2189
C(α),O-oximes were dilithiated with lithium diisopropylamide and condensed with three α,β-unsaturated ketones: (2E)-1,3-diphenyl-2-propen-1-one, or (1E, 4E)-1,5-diphenyl-1,4-pentadien-3-one, or (3E)-4-phenyl-3-buten-2-one, followed by immediate acid cyclization to variously substituted 4,5-dihydroisoxazoles: 4,5-dihydro-5-phenyl-5-(2-phenylethenyl)isoxazoles, 4,5-dihydro-5-methyl-5-(2-phenylethenyl)isoxazoles, or 4,5-dihydro-5,5-di-(2-phenylethenyl)-isoxazoles. 相似文献
19.
Cyclization of 2-carbomethoxy-3-(4',4'-dimethylcyclopent-2-enylmethyl)cyclopentanone (4) with N-phenylselenophthalimide and tin(IV) chloride affords cis-syn-cis-1β-carbomethoxy-4,4-dimethyl-3β-phenylselenotricyclo [6.3.0.02,6]undecan-11-one (8) and cis-anti-cis-1β-carbomethoxy-4,4-dimethyl-3α-phenylselenotricyclo [6.3.0.02,6]undecan-11-one (9). Both of these selenides can be elaborated to cis-anti-cis-4,4-dimethyl-1β-methyltricyclo [6.3.0.02,6]undecan-11-one (13) which upon treatment with CH2Br2/ TiCl4/Zn affords the sesquiterpene (±)-hirsutene (1) in 20% overall yield. 相似文献
20.
A method for preparing haloconduritols having a conduritol-A construction is described. A mixture of endo- and exo-cycloadduct derivatives prepared from the Diels-Alder reaction of furan and vinylene carbonate was converted into diacetate derivatives by hydrolysis (K2CO3/MeOH) followed by acetylation (Ac2O/pyridine). Boron trihalide (BBr3 or BCl3)-assisted ring-opening of the endo-diacetate in CH2Cl2 at −78°C gave (1α,2α,3β,6β)-6-halogeno-4-cyclohexene-1,2,3-triol 1,2-diacetate from which the corresponding triacetate was prepared by acetylation (AcCl). trans-Esterification of the triacetate (MeOH/HCl) afforded (1α,2α,3β,6β)-6-halogeno-4-cyclohexene-1,2,3-triol (X=Br or Cl). BF3-Assisted ring-opening of the endo-diacetate in CH2Cl2 gave (1α,2α,3β,6β)-6-chloro-4-cyclohexene-1,2,3-triol 1,2-diacetate by means of halogen exchange. 相似文献