438-22-2Relevant articles and documents
A Geomimetic Approach to the Formation and Identification of Fossil Sterane Biomarkers in Crude Oil: 18-nor- D -homo-Androstane and 5α,14β-Androstane
Bender, Matthias,Schmidtmann, Marc,Summons, Roger E.,Rullk?tter, Jürgen,Christoffers, Jens
, p. 12501 - 12508 (2015/08/25)
A diazonium ion derived from 18-aminoandrostane rearranged upon decomposition by a carbonium and a carbenium ion to furnish a mixture of a cyclopropanated compound and two D-homo-androstenes. Hydrogenation of this mixture gave the saturated hydrocarbons, 18-nor-D-homo-androstane and 5α,14β-androstane, which are both fossil sterane biomarkers in Neoproterozoic crude oil. The so far unknown constitution and configuration as well as the geochemical genesis were established by this experiment. The starting material for this investigation, 18-aminoandrostane, was prepared in twelve steps from androstan-17-one (12.5% overall yield) with a Barton reaction as the key step.
Steroidal alkenylphosphonates via palladium-catalyzed coupling reactions
Skoda-Foeldes, Rita,Kollar, Laszlo,Horvath, Judit,Tuba, Zoltan
, p. 791 - 795 (2007/10/02)
The palladium-catalyzed coupling of various 17-iodo-Δ16 steroids (17-iodo-androst-16-ene, 17-iodo-4-methyl-4-aza-androst-16-en-3-one, and 17-iodo-4-aza-androst-16-en-3-one) with dialkyl phosphites (dimethyl phosphite, diethyl phosphite, and diisopropyl phosphite) was examined in detail.The only successful condition for homogeneous coupling involved carrying out the reaction in the absence of any solvents.A large excess of dialkyl phosphite was used, which means that the phosphite itself acted as a solvent.Eight new androst-16-ene derivatives with phosphonate groups at C-17 were synthesized and characterized.These steroids are of pharmacological interest as potential 5α-reductase inhibitors.Under the same conditions, methylation of lactam NH was observed using dimethyl phosphite. - Keywords: coupling reaction of steroids; steroidal alkenylphosphonates; homogeneous palladium(0) catalysts
Synthesis in the 5-alpha, 13-alpha androstane series
Fetizon,Gramain
, p. 1003 - 1009 (2007/10/05)
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