Displacement Reactions. IX. The Reaction of Cyanide Ion with Cystine. An Example of Amino Group Participation as Detected with Nitrogen-15 during Cleavage of a Sulfur-Sulfur Bond1

1966 ◽  
Vol 88 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Eugene Stephen Wagner ◽  
Robert Earl Davis
Keyword(s):  
Amino Group ◽  
Cyanide Ion ◽  
Group Participation ◽  
Displacement Reactions

Pteridines CX

Pteridines ◽  
1999 ◽  
Vol 10 (3) ◽  
pp. 79-90 ◽  
Author(s):  
Hermann Traub ◽  
Wolfgang Pfleiderer
Keyword(s):  
Functional Groups ◽  
Side Chain ◽  
Amino Group ◽  
Nucleophilic Displacement ◽  
Acid And Base ◽  
Displacement Reactions ◽  
Amide Acetals

Summary A series of new 6-substituted 2,4-diaminopteridines (3-23) and pterins (26-43) have been synthesized by nucleophilic displacement reactions at the side chain of 6-bromomethyl-2,4-diaminopteridine (2) and 6- bromomethylpterin (25) using various types of 0-, N- and S-nucleophiles. Acid and base hydrolyses allow easy conversion of the 2,4-diaminopteridines (3-5, 7, 9, 10, 12, 19-21 and 23) into the corresponding pterins (26-32, 39-42). Acylations take place at the amino as well as at the functional groups in the side chain (44-46). A versatile protection of the amino group in pterins is its transformation into the N ,N -dimethylaminomethylcnimino function by amide-acetals (47, 50) allowing subsequently selective acylations at the side chain (48, 49).

Dihydrotestosterone with an Ammonium Centre in the Position 16β

1997 ◽  
Vol 62 (4) ◽  
pp. 656-664 ◽  
Author(s):  
Barbora Slavíková ◽  
Alexander Kasal ◽  
Miloš Buděšínský
Keyword(s):  
Quaternary Ammonium ◽  
Water Soluble ◽  
High Yield ◽  
Partial Hydrolysis ◽  
Amino Group ◽  
Alternative Synthesis ◽  
Group Participation ◽  
Neighbouring Group Participation ◽  
Hydrolysis Of

In an alternative synthesis of 17β-hydroxy-16β-(piperidin-1-yl)-5α-androstan-3-one (4), neighbouring group participation between a 17β-carbonyloxy group and the 16β-amino group was used and a high yield partial hydrolysis of 3β,17β-diacetoxy-16β-(piperidin-1-yl)-5α-androstane (11) was developed. Interference of the neighbouring group participation was also apparent in another 17β-acetoxy derivative - in oxidation of compound 12 to 13. Compound 4 was converted into water-soluble derivatives, i.e. quaternary ammonium derivatives 17 to 20.

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