| abstract |
Non-natural amino acids such as 2 -alkylated amino acids allow for the synthesis of a wider variety of peptidal and non-peptidal pharmaceutically active agents. In one embodiment, the present invention relates to a method of preparing a 2 -alkylcysteine comprising condensing cysteine with an aryl nitrile to form a 2 -arylthiazoline- 4 -carboxylic acid, esterifying the 2 -arylthiazoline- 4 -carboxylic acid using a substituted or unsubstituted alcohol group comprising one or more chiral carbons, and alkylating at the 4 -position of the thiazoline ring to form a 2 -aryl- 4 -alkyl-thiazoline- 4 -carboxylic acid ester. The chiral templates present in the thiazoline carboxylic acid ester can provide face selectivity, and consequently desired stereochemistry, during the delivery of an alkyl group to the 4 -position of the thiazoline ring. The present invention also discloses a method of preparing a class of iron chelating agents related to desferrithiocin, all of which contain a thiazoline ring. In one embodiment, an aryl nitrile is condensed with cysteine or a 2 -alkyl cysteine. |