Two efficient and practical methods of synthesis of the C-10 substituent of DV-7751 (1), a novel quinolone carboxylic acid, were established. The first method utilizes an optical resolution of racemic 8-amino-6-benzyl-6-azaspiro[3.4]octane (13), while the second employs an enantioselective microbial reduction of 6-benzyl-5,8-dioxo-6-azaspiro[3.4]octane (8b). The enantiomeric excess of (S)-8-ami...

Enantiomerically pure secondary alcohols were prepared in the combined CAL-B/VOSO4 system one-pot conditions. Under optimum conditions, conversion, enantiomeric excess, selectivity and enantioselectivity reached 92%, >99%, 99% >200 respectively. The significant improvement of performance should be attributed to mutual coordination reactions a chemoenzymatic dynamic kinetic resolution redu...

The ?-blocker (S)-bisoprolol hemifumarate has been synthesised in 96% enantiomeric excess with 19% total yield a six-step synthesis. A transesterification reaction of the racemic chlorohydrin 1-chloro-3-(4-((2-isopropoxyethoxy)methyl)phenoxy)propan-2-ol catalysed by lipase B from Candida antarctica resulted R-chlorohydrin high purity. Reaction this building block isopropylamine methanol gave (S...

Introduction: The finding of slight to significant enanti-omeric excesses for several indigenous amino acids in the Mur-chison and Murray CM-type meteorites [1-3] could point toward an exogenous origin of biological homochirality on the early Earth. UV circularly polarized light (UV-CPL) in the presolar cloud has been proposed as one possible source of the initial amino acid symmetry [4]. Howev...

Abstract In this study, chiral bis(pyrazolyl)methane copper(I) acetonitrile complexes were applied to generate two novel terminal copper tosyl nitrene with the generating agent S PhINTs in dichloromethane at low temperatures. The syntheses of ligands are based on pulegone and camphor, members natural pool. as catalysts mediated aziridination reaction different styrene derivatives C–H amination ...

The study by Duarte et al. 1 confirmed the theoretical fundaments by which enantiomeric excess bupivacaine or enantiomeric mixture of bupivacaine was developed. When we developed this drug, we geared the pre-clinical phase to study whether handling of the isomers regarding their ability to block the nerve would be possible. For such, the mice sciatic nerve was used. Once confirmed the activity ...

BACKGROUND AND OBJECTIVES Hyperbaric bupivacaine is commercially available in its racemic form. In Brazil, 50% enantiomeric excess bupivacaine (S75:R25) was introduced as an isobaric presentation. The objective of this study was to evaluate different volumes of hyperbaric S75:R25 bupivacaine in spinal blocks for infraumbilical surgeries. METHODS Forty patients, ages 20 to 60 years, physical s...

Traditionally, reaction conversion and enantiomeric excess (% ee) of products are monitored using two separate HPLC or GC systems, one system for monitoring the reaction conversion and the other system for determining the % ee. In addition, in-process samples are usually sampled manually, limiting the continuous monitoring of reaction process. For the first time, a fully automated on-line achir...

We have previously shown that vanadium bromoperoxidase from Ascophyllum nodosum mediates production of the (R)-enantiomer of methyl phenyl sulfoxide with 91% enantiomeric excess. Investigation of the intrinsic selectivity of vanadium bromoperoxidase reveals that the enzyme catalyzes the sulfoxidation of methyl phenyl sulfide in a purely enantioselective manner. The K(m) of the enzyme for methyl...