174060-99-2Relevant articles and documents
HIV PROTEASE INHIBITORS, COMPOSITIONS CONTAINING THE SAME AND THEIR PHARMACEUTICAL USES
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Page/Page column 108, (2010/02/11)
This invention relates to a novel series of chemical compounds useful as Human immunodeficiency Virus (HIV) protease inhibitors and to the use of such compounds as antiviral agents. The invention further relates to pharmaceutical compositions containing s
Regioselective enolization and alkylation of 4-oxo-N-(9-phenylfluoren-9-yl)proline: Synthesis of enantiopure proline-valine and hydroxyproline-valine chimeras
Sharma, Raman,Lubell, William D.
, p. 202 - 209 (2007/10/03)
The regioselective enolization of 4-oxo-N-(9-phenylfluoren-9-yl)proline benzyl ester (5) followed by alkylation with different alkyl halides has been used to synthesize a variety of β-alkylproline derivatives. In particular, enolization of 5 with 400 mol % of KN(SiMe3)2 and alkylation with iodomethane provided 3,3-dimethyl-4-oxo-N-(9-phenylfluoren-9-yl)proline benzyl ester (7a) in excellent yield. Subsequent hydride reduction of ketone 7a and protecting group exchange by hydrogenation in the presence of di-tert-butyl dicarbonate provided enantiopure (2S,4R)- and (2S,-4S)-3,3-dimethyl-4-hydroxy-N-(BOC)prolines 2. Hydroxyproline-valine chimeras (2S,4R)- and (2S,4S)-2 are each synthesized from hydroxyproline in six steps and 27% respective overall yield. Deoxygenation of 3,3-dimethyl-4-hydroxy-N-(9-phenylfluoren-9-yl)proline benzyl esters 9 via their conversion to xanthates 10 followed by tributylstannane-mediated reduction provided 3,3-dimethyl-N-(9-phenylfluoren-9-yl)proline benzyl ester (11) in excellent yield. Hydrogenation of 11 with Pearlman's catalyst in the presence of di-tert-butyl dicarbonate then furnished (2S)-3,3-dimethyl-N-(BOC)proline (1) in the last step of an eight-step synthesis (41% overall yield) from hydroxyproline. Both proline-valine and hydroxyproline-valine chimeras 1 and 2 were designed to serve as tools for studying the conformational requirements of biologically active peptides.