92471-85-7Relevant academic research and scientific papers
Trichosporon beigelli esterase (TBE): A versatile esterase for the resolution of economically important racemates
Koul, Surrinder,Koul, Jawahir Lal,Singh, Budh,Kapoor, Munish,Parshad, Rajinder,Manhas, Kuldeep S.,Taneja, Subhash C.,Qazi, Ghulam N.
, p. 2575 - 2591 (2007/10/03)
A hydrolase producing strain Trichosporon beigelli esterase (TBE) isolated from local cottage cheese in its native form has displayed versatility and high efficacy in the kinetic resolution of a wide range of economically important substrates, which include racemic secondary alcohols, such as 1-(6-methoxy-2-naphthyl)ethanol (E ～ 316), 1-(3,4-methylenedioxyphenyl) ethanol and pentanol (E ～ 180 and 156 resp.), and alkyl esters of carboxylic acids such as ibuprofen (E ～ 340), 2-(benzylthio)propanoic acid (E ～ 1000). In other substrates such as in the primary alcohol 2-(6-methoxy-2- naphthyl)propan-1-ol and carboxylic acids such as 2-(5-bromo-6-methoxy-2- naphthyl)propanoic acid, 2-(2-naphthyloxy)propanoic acid, and substituted 2-thiopropanoic acids, it displayed moderate to low selectivity. Commercial lipases such as CCL, PPL, and PSL were also used in the resolution of the substrates for comparative studies.
A STEREOCONVERGENT STRATEGY FOR THE SYNTHESIS OF ENANTIOMERICALLY PURE (R)-(-) AND (S)-(+)-2-(6-METHOXY-2-NAPHTHYL)-PROPANOIC ACID (NAPROXEN)
Giordano, Claudio,Castaldi, Graziano,Cavicchioli, Silvia,Villa, Marco
, p. 4243 - 4252 (2007/10/02)
A synthetic strategy for resolving diastereoselective imperfections associated with using a chiral auxillary has been designed.The impact of this imperfection is a lower enantiomeric purity of the final product.A solution for the synthesis of Naproxen 1, an important antiinflammatory drug, using tartaric acid as chiral auxillary, derives from an equivalent of a kinetic resolution.Using the differential rate of a rearrangement versus an intramolecular carboxylate alkylation, enantiomerically pure Naproxen 1 can be obtained from diastereomeric mixtures of bromo acetals diacids 9a, b enriched in 9a.Furthermore, the product coming from the intramolecular carboxylate alkylation of the minor diastereomer 9b is also converted into Naproxen 1.This stereoconvergence permits complete productive utilization of the diastereomeric mixture 9a, b.
Tartaric Acid, an Efficient Chiral Auxiliary: New Asymmetric Synthesis of 2-Alkyl-2-arylacetic Acids
Castaldi, Graziano,Cavicchioli, Silvia,Giordano, Claudio,Uggeri, Fulvio
, p. 3018 - 3027 (2007/10/02)
A highly enantioselective synthesis of 2-alkyl-2-arylacetic acids, an important class of antiinflammatory agents, based on a new diastereoselective α-bromination of homochiral acetals 1 and on the stereospecific silver-promoted rearrangement of the corresponding homochiral α-bromo acetals 2 and 3, is reported.The new methodology represents a meaningful example of the use of tartaric acid as efficient and economic chiral auxiliary.The asymmetric bromination of 1 is of general character and occurs with very high diastereoselectivity, even at room temperature; a mechanism for the new reaction is proposed.The overall process has been successfully applied to the preparation of enantiomerically pure 2-alkyl-2-arylacetic acids, among them (2S)-(+)-2-(6-methoxy-2-naphthyl)propanoic acid (Naproxen)
