STEROIDS AND RELATED PRODUCTS: XIX. THE SYNTHESIS OF 3,9,12,20-TETRAOXYGENATED 9,12-seco STEROIDS. PART III. 11-AZA STEROIDS. PART I

1962 ◽  
Vol 40 (11) ◽  
pp. 2153-2162 ◽  
Author(s):  
Ch. R. Engel ◽  
S. Rakhit
Keyword(s):  
Methyl Ester ◽  
Ethylene Glycol ◽  
Ethyl Acetate ◽  
Good Yield ◽  
Boron Trifluoride ◽  
Osmium Tetroxide ◽  
Periodic Acid ◽  
Boron Trifluoride Etherate ◽  
The Other ◽  
Other Hand

The smooth conversion of 3β-acetoxy-5α-pregnane-12,20-dione (IV), readily available from hecogenin (I), to Δ9(11)-3β,20β-diacetoxy-5α-pregnan-12-one (VIII) is reported. Ozonolysis of this product in ethyl acetate gave, in almost 90% yield, 3β-hydroxy-20β-acetoxy-9-oxo-9,12-seco-11-nor-5α-pregnan-12-oic acid (XI), further characterized by its ester derivatives XIa and XIb. The conversion of the seco acid XI to Δ8(9)-3β-hydroxy-20β-acetoxy-9-amino-9,12-seco-11-nor-5α-pregnen-12-oic acid lactam (12 → 9) (XII) and thence to Δ8(9)-N-acetyl-3β,20β-diacetoxy-11-aza-5α-pregnene (XIVa), the first 11-aza steroids to be known, is described. On the other hand, Δ9(11)-3β,20β-diacetoxy-5α-pregnen-12-one (VIII) is readily transformed to the 9α,11α-glycol VII with osmium tetroxide and thence, with periodic acid, to 3β,9α-dihydroxy-20β-acetoxy-11-oxo-11,12-seco-5α-pregnan-12-oic acid (X), characterized as the methyl ester Xa and diacetoxy methyl ester Xb, and easily converted to the acetoxy hydroxy keto dicarboxylic seco acid XIII. In the course of this work it is shown that, whereas ketalization of the saturated 12,20-diketone IV with ethylene glycol and boron trifluoride etherate gives a good yield of the 12-monoketal (in accordance with the reports of the literature), treatment of the analogous 16-unsaturated 12,20-diketone with the same reagents under the same conditions leads not to ketal formation but to addition of ethylene glycol in position 16.

Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

1966 ◽  
Vol 16 (01/02) ◽  
pp. 018-031 ◽  
Author(s):  
S Sherry ◽  
Norma Alkjaersig ◽  
A. P Fletcher
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Comparative Studies ◽  
Esterase Activity ◽  
Methyl Esters ◽  
Hydrolytic Activity ◽  
The Other ◽  
Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

Synthesen von Heterocyclen, CCIV1 Reaktionen mit cyclischen Oxalylverbindungen, XIX2 Eine einfache Synthese von 5-Benzoyl-6-phenyl-1.3-dioxin-4-onen / Syntheses of Heterocycles, CCIV1 Reactions of Cyclic Oxalyl Compounds, XIX 2 A Simple Synthesis of 5 Benzoyl-6-phenyl-1,3-dioxin-4-ones

1977 ◽  
Vol 32 (6) ◽  
pp. 701-704 ◽  
Author(s):  
Gert Kollenz ◽  
Erich Ziegler ◽  
Walter Ott ◽  
Gert Kriwetz
Keyword(s):  
Acetic Acid ◽  
Methyl Ester ◽  
Acrylic Acid ◽  
Acid Methyl Ester ◽  
The Other ◽  
Simple Synthesis ◽  
Acid Methyl ◽  
Other Hand

4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione (1) reacts with aldehydes or ketones via the acylketene-intermediate (2) yielding the 1,3-dioxin-4-ones (3). The aldehyde derivatives (3 a-e) can be converted into the anilino-chalcone (5) or the anilino acrylic acid (6) by treating with aniline at 20 °C. 6 and diazomethane combine to the acrylic acid methyl ester (7), which by heating (200 °C) is cyclisized to the quinolin-4-ole (8). On the other hand, the keto derivatives 3f-h and aniline give the dibenzoyl acetic acid anilide (9).

STEROIDS AND RELATED PRODUCTS: VII. THE SYNTHESIS OF 17α-METHYLCORTICOSTERONE

1957 ◽  
Vol 35 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Ch. R. Engel
Keyword(s):  
Ethylene Glycol ◽  
Biologically Active ◽  
The Other ◽  
Keto Group ◽  
Methyl Group ◽  
Other Hand ◽  
Hydrolysis Of

The synthesis of 17α-methylcorticosterone, a new biologically active homologue of corticosterone and analogue of cortisol, is described. In the course of the work it was observed that the 17-methyl group greatly impeded both the formation and the hydrolysis of a 20-ketal. On the other hand, evidence was obtained that the 11-keto group is not completely unreactive towards ethylene glycol, in the presence of p-toluenesulphonic acid.

Notizen: Zur Reaktion von En-diolen mit Halogendisilanen.

1976 ◽  
Vol 31 (5) ◽  
pp. 694-695 ◽  
Author(s):  
E. Hengge ◽  
E. Brandstätter
Keyword(s):  
Good Yield ◽  
The Other ◽  
Other Hand ◽  
Membered Heterocycle

Alkalistilbenolate does not react, as expected, with dichlorotetramethyldisilane (1) to a six-membered heterocyclic, but the SiSi linkage is nucleophilic attacked by the oxygen and a five-membered heterocycle with only one Si-atom is formed. On the other hand, 1,2-dihydroxybenzene reacts with 1 to the new six-membered heterocycle in good yield.

Synthesis of 5-tert-butyl-8,12,14-trimethyl- and 5-tert-butyl-8,12,14,16-tetramethyl[2.2]metacyclophane and their treatment with Lewis acids in benzene

2009 ◽  
Vol 2009 (7) ◽  
pp. 443-447 ◽  
Author(s):  
Tomoe Shimizu ◽  
Katsuhiko Hida ◽  
Takehiko Yamato
Keyword(s):  
Good Yield ◽  
Lewis Acids ◽  
The Other ◽  
Tert Butyl ◽  
Other Hand

Treatment of 5- tert-butyl-8,12,14,16-tetramethyl[2.2]MCP with AlCl3-MeNO2 in benzene led to trans- tert-butylation to afford 8,12,14,16-tetramethyl[2.2]MCP in good yield along with tert-butylbenzene. On the other hand, the same treatment of 5- tert-butyl-8,12,14-trimethyl[2.2]MCP led to transannular cyclisation reaction and isomerisation reaction to afford the corresponding strainless 2- tert-butyl-3a,6,8-trimethyl-3,3a,4,5,9,10-hexahydropyrene in good yield.

Bufadienolides. 17. Synthesis of 14α- and 14β-Artebufogenin

1973 ◽  
Vol 51 (12) ◽  
pp. 1973-1976 ◽  
Author(s):  
Yoshiaki Kamano ◽  
George R. Pettit
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Perchloric Acid ◽  
Boron Trifluoride ◽  
Periodic Acid ◽  
Boron Trifluoride Etherate ◽  
Similar Reaction ◽  
Analogous Reaction ◽  
Dihydroxy Derivative

Treatment of resibufogenin (1a) or its acetate (1b) with perchloric acid or hydrochloric acid gave 14α-and 14β-artebufogenin (5a and 6a, or 5b and 6b), in addition to 15α-hydroxy-bufalin (4a or b). Reaction of epoxide 1b with chloranil or boron trifluoride etherate easily afforded 14α- and 14β-artebufogenin acetate (5b and 6b) in good yields. Analogous reaction of the isomeric 3β-hydroxy-14α,15α-epoxide 3a with perchloric acid, hydrochloric acid, or sulfuric acid again led to 14α- and 14β-artebufogenin (5a and 6a) and the 14β,15α-dihydroxy-derivative 4a, Similar reaction with periodic acid gave 6a and 4a.

scholarly journals ZSM-5 Filled Polyether Block Amide Membranes for Separating EA from Aqueous Solution by Pervaporation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jin Gu ◽  
Xinran Zhang ◽  
Yunxiang Bai ◽  
Le Yang ◽  
Chunfang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ethyl Acetate ◽  
Separation Factor ◽  
The Other ◽  
Total Flux ◽  
Feed Concentration ◽  
Similar Variation ◽  
Other Hand

ZSM-5 filled polyether block amide membranes (PEBA), PEBA/ZSM-5, were prepared and used to recover aroma, ethyl acetate (EA), from aqueous solution by pervaporation (PV). The membranes demonstrated high EA permselectivity, and with the increase of ZSM-5 loading, the separation factor increased initially and then decreased, while the total flux demonstrated the similar variation until the ZSM-5 loading was 10 wt%, at which it reached the lowest value. After that, it began to increase again. On the other hand, the separation factor, and total flux of the PEBA/ZSM-5 membrane containing 10 wt% ZSM-5, PEBA/ZSM-5-10, increased with the increase of feed concentration and temperature. The best PV performance, separation factor and total flux of PEBA/ZSM-5-10 membrane were 185.5 and 199.5 gm−2h−1, respectively, with feed concentration of 5 wt% EA at 50°C.

Synthesis of 2-Acetoacetyl- and 2-OxaIoacetyl-1,3-indandiones and Related Compounds

1988 ◽  
Vol 43 (7) ◽  
pp. 897-900 ◽  
Author(s):  
W. S. Hamama ◽  
M. Hammouda ◽  
E. M. Afsah
Keyword(s):  
Ethyl Acetate ◽  
Mannich Reaction ◽  
Selenium Dioxide ◽  
The Other ◽  
Molar Ratio ◽  
Diethyl Oxalate ◽  
Phenyl Hydrazine ◽  
Claisen Condensation ◽  
Other Hand ◽  
Related Compounds

Abstract Claisen condensation of 2-acetyl-1,3-indandione (1) with ethyl acetate afforded the 2-acetoacetyl-1,3-indandione (2) which upon treatment with benzylamine and paraformaldehyde in a molar ratio of (1:1:2) and (1:2:4) afforded the piperidinone and the diazabicyclic derivative (4) and (5) respectively. On the other hand, Claisen condensation of 1 with diethyl oxalate yielded two products (6) and (9). The behaviour of 6 towards phenyl hydrazine, and of 9 towards selenium dioxide and double Mannich reaction were also investigated.

Enolic Ortho Esters. IV. Synthesis of the 8-α and 8-β Epimers of a 6-Oxa Steroidal Enolic Ortho Ester

1989 ◽  
Vol 42 (10) ◽  
pp. 1769 ◽  
Author(s):  
DJ Collins ◽  
AG Jhingran ◽  
SB Rutschmann
Keyword(s):  
Ethylene Oxide ◽  
Ethylene Glycol ◽  
Boron Trifluoride ◽  
Methanesulfonic Acid ◽  
Boron Trifluoride Etherate ◽  
Ortho Ester ◽  
Birch Reduction ◽  
Ortho Esters

Reaction of resorcinol (9) with methyl 1β-hydroxy-7aβ-methyl-5-oxo-2,3,3 a α,4,5,6,7,7a- octahydro-1H-indene-4α-carboxylate (10a) or with the corresponding 1,5-dioxo ester (15) in methanesulfonic acid gave ( �)-3,17 β-dihydroxy-6-oxaestra-l,3,5(10),8(9)-tetraen-7-one (11a) (98%), or (c)-3-hydroxy-6-oxaestra-1,3,5(10),8(9)-tetraene-7,17-dione (14) (91%), respectively. 3-O-Methylation of the phenolic keto lactone (14) followed by reaction with ethylene glycol gave (�)-17,17-ethylenedioxy-3-methoxy-6-oxaestra-1,3,5(10),8(9)- tetrae n-7-one (16). Reduction of this with lithium/ammonia afforded 77% of (�) 17,17-ethylenedioxy-3-methoxy-6-oxa-8 α-estra-1,3,5(10)-trien-7-one (71, which upon base-catalysed epimerization yielded 84% of the 8 β-epimer (19). Reaction of the 8 α-H lactone (17) or its 8 β- epimer (19) with ethylene oxide in the presence of boron trifluoride etherate yielded the corresponding phenolic ortho esters (�)-7,7:17,17-bis( ethylenedioxy )-3-methoxy-6-oxa-8 α-estra-1,3,S(10)- triene (23), and its 8 β- epimer (25), in 36 and 42% yields, respectively. Birch reduction of (23) and (25) afforded the corresponding enolic ortho ester ( �)-7,7:17,17-bis( ethylenedioxy )-3-methoxy-6-oxa-8 α-estra-2,5(10)- diene (26), and its 8 β-epimer (6), in 82 and 64% yields, respectively. Some related chemistry is described. The enolic ortho esters (26) and (6) were relatively inert to attack by methylmagne sium iodide under normal conditions.

Digitoxigenin-3-alkyl ethers

1981 ◽  
Vol 59 (7) ◽  
pp. 1025-1027 ◽  
Author(s):  
Robert Greenhouse ◽  
Joseph M. Muchowski
Keyword(s):  
Ethylene Glycol ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Alcoholic Medium ◽  
The Third ◽  
Alkyl Ethers

The synthesis of the title compounds was accomplished by (i) boron trifluoride etherate catalysed alkylation of digitoxigenin with diazoalkanes, (ii) silver tetrafluoroborate assisted solvolysis of 3-desoxy-3α-iododigitoxigen 2d in an alcoholic medium, and (iii) m-chloroperbenzoic acid induced oxidative solvolytic displacement on the iodo compound 2d in the presence of alcohols. The third process was the most useful for the preparation of the mono ethers 2e and 2f of ethylene glycol and glycerol, respectively.

Sign in / Sign up

Export Citation Format

Share Document