- A Practical Route for Enantioselective Total Synthesis of (+)-11-Deoxy-19-norcorticosterone via Intramolecular Diels-Alder Addition to an ortho-Quinodimethane
-
A convenient and practical route for enantioselective synthesis of the A-nor-B-trienic steroid 2 via an intramolecular cycloaddition of the olefinic ortho-quinodimethane 3 generated in situ by thermolysis of the olefinic benzocyclobutene 4 is report
- Nemoto, Hideo,Satoh, Atsushi,Ando, Masahiro,Fukumoto, Keiichiro
-
p. 1309 - 1314
(2007/10/02)
-
- Process for the synthesis of the hydroxyacetyl side-chain of steroids of the pregnane type, novel 21-hydroxy-20-oxo-17α-pregnane compounds and pharmaceutical preparations containing them
-
The present invention relates to a novel general process for synthesizing a α- or β-oriented hydroxyacetyl side chain of steroids of the pregnane type, which comprises treating a corresponding steroid carbaldehyde in succession with formaldehyde dimethylmercaptal-S-oxide in the form of an alkali metal salt thereof, and with a strongly acid hydrolysing agent.Preferred final products are compounds of the formula STR1 wherein n is 1 or 2, R 2 represents methyl or difluoromethyl, and R 1 represents hydroxymethyl, methoxymethyl, acetoxymethyl or hydrogen, and, if n is 2 and/or R 2 is difluoromethyl, R 1 also represents methyl. These compounds act as agonists or antagonists of natural steroid hormones. The antigestagenic 19,21-dihydroxy-17α-pregn-4-ene-3,20-dione and its 6,7-dehydro derivatives and diacetates are of particular interest.
- -
-
-
- New Syntheses of 19,21-Dihydropregn-4-ene-3,20-dione, 21-Hydroxy-19-norpregn-4-ene-3,20-dione, and 11β,19,21-trihydroxypregn-4-ene-3,20-dione
-
19,21-Dihydroxypregn-4-ene-3,20-dione has been synthesized from 3β-acetoxypregn-5-en-20-one via the "hypoiodite reaction" , and Henbest acetoxylation at C-21; oxidation of the intermediate 21-monoacetate to 19-oxo derivative and alkaline cleavage gave 21-hydroxy-19-norpregn-4-ene-3,20-dione.A similar synthesis of 11β,19,21-trihydroxypregn-4-ene-3,20-dione from 3β-acetoxypregn-5-ene-11,20-dione proceeded through intermediates with the 11β-hydroxy function protected as its acetate.Unusual features mainly of conformational origin were observed in the presence of the 11β-acetoxy substituent; some were helpful to the synthesis, while others led to undesirable side reactions.
- Kirk, David N.,Yeoh, Boon Leng
-
p. 2945 - 2952
(2007/10/02)
-
- Simple Route for Elaboration of the Hydroxy-ketone and Dihydroxy-acetone Side-chains of Corticosteroids from 17-Oxo-steroids
-
α-Formylaminoacrylic esters, produced by the condensation of ethyl isocyanoacetate with 17-oxo-steroids have been reduced selectively to give the corresponding alcohols; the latter gave, in high yield, the hydroxyacetyl side-chain on acidic hydrolysis or the dihydroxy-acetone side-chain after appropriate oxidation and hydrolysis.
- Nedelec, Lucien,Torelli, Vesperto,Hardy, Michel
-
p. 775 - 777
(2007/10/02)
-