Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• manner was reported by Chu et al. [22]. Choi et al. [23] produced the 5-fluoro-substituted analogue of a 1,3-oxathiolane nucleoside as a racemic mixture, and the enantiomers were separated using pig liver esterase (PLE) enzyme, which resulted in 5’-butyroyl ester derivatives. They further explained the

A mechanochemical approach to access the proline–proline diketopiperazine framework

• Nicolas Pétry,
• Hafid Benakki,
• Eric Clot,
• Pascal Retailleau,
• Farhate Guenoun,
• Fatima Asserar,
• Chakib Sekkat,
• Thomas-Xavier Métro,
• Jean Martinez and
• Frédéric Lamaty

Beilstein J. Org. Chem. 2017, 13, 2169–2178, doi:10.3762/bjoc.13.217

• liver esterase (PLE)-catalyzed enzymatic hydrolysis of meso cis-11 provided selectively the N-protected amino acid 17 as one enantiomer [33][44][45]. Mechanocoupling of 17 with pyrrolidine 12 provided the dipeptide 18 in excellent yield. Removal of the benzyl group by hydrogenation in the presence of Pd

• . This was in agreement with the experimental formation of only 15a. As mentioned above, another possibility to exploit meso pyrrolidine cis-11 would be to desymmetrize [43] the ester functions by selective hydrolysis. The corresponding carboxylic acid could then be engaged in a peptide coupling. Pig

Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

• Frank Hahn,
• Nadine Kandziora,
• Steffen Friedrich and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 634–640, doi:10.3762/bjoc.10.55

• monitored by mass spectrometry. After two days, complete TBS removal was obtained. The crude product was subjected to selective methyl ester cleavage by using pig liver esterase (PLE) [24]. The target molecule was obtained as a mixture of both anti-diastereomers 5a and 5b after 15 steps in 7% overall yield

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• Information File 1) were exposed to pig-liver esterase (PLE), the porcine homologue of carboxylesterase, in buffered aqueous solution. Fluoroacetamide 19 was prepared by reacting 4-fluoroaniline with fluoroacetyl chloride. The activity of the enzyme preparation was verified using the chromogenic standard

Oxidative allylic rearrangement of cycloalkenols: Formal total synthesis of enantiomerically pure trisporic acid B

• Silke Dubberke,
• Muhammad Abbas and
• Bernhard Westermann

Beilstein J. Org. Chem. 2011, 7, 421–425, doi:10.3762/bjoc.7.54

• resolution; natural products; oxidative rearrangement; pig liver esterase (PLE); trisporic acid B; Introduction The generation of chiral, non-racemic compounds bearing a stereogenic quaternary carbon centre is of great interest [1][2][3][4][5][6][7][8]. Therefore, much effort has been directed towards the

• synthesis of this stereogenic unit and solutions have been found, e.g., by Christoffers and d’Angelo [9][10][11]. We have already disclosed our results to obtain these products highly enantiomerically enriched by pig liver esterase (PLE) catalyzed saponification of α-substituted β-ketoesters [12][13]. We

• -ketoester 1c, the racemate 1c is resolved by a pig liver esterase (PLE)-catalyzed saponification reaction. As in other cases reported earlier, the racemic β-ketoesters are hydrolyzed with high stereoselectivity allowing the isolation of optically pure esters (–)-1. The corresponding hydrolysis products, the