Ahmed F. Abdel-Magid

Hydrolysis of polypeptide esters with tetrabutylammonium hydroxide

Abstract Tetrabutylammonium hydroxide is effective in hydrolysis of polypeptide esters to the corresponding acids with minimum racemization of the stereogenic centers at the α-positions. It is especially effective in hydrolysis of non-polar polypeptide esters that are insoluble in most common solvents.

A predominately anti-stereoselective chiral metal directed aldol condensation with aromatic aldehydes

Abstract Chiral haloacetyl oxazolidinones were reacted with aromatic aldehydes via their kinetically generated Z-enolates to yield predominately anti aldol adducts. The reaction is postulated to proceed thru a boat-like transition state. A unique reversal of chirality was observed in using stannous enolates.

An efficient stereoselective synthesis of methyl (S)-3-amino-3-(3-pyridyl)propanoate

Methyl (S)-3-amino-3-(3-pyridyl)propanoate (2) is a key starting material in the synthesis of RWJ-53308 (1), an orally active antagonist of the platelet fibrinogen receptor (GP IIb/IIIa antagonist). Herein, we describe an efficient stereoselective synthesis of 2 by the hydrogenation of enantiomeric enamine 8 with Pd(OH)2C, followed by the removal of the chiral auxiliary under mild conditions, a novel procedure that employs the combination of formic acid and triethylsilane.

Chemical process research : the art of practical organic synthesis

This book shows the diversity of structural problems and synthesis solution as well as the practical aspects and methodologies required for large-scale syntheses. The eleven chapters focus on chemical process research in the pharmaceutical industry.