Nanomole-Scale Assignment and One-Use Kits for Determining the Absolute Configuration of Secondary Alcohols.

Two different protocols were developed and optimized to address the need for (1) high sensitivity or (2) convenient utilization in the determination of the absolute configuration of secondary alcohols. The first protocol uses the competing enantioselective conversion (CEC) method to determine configuration on nanomole scale. Reactions were conducted with 145 nmol of the substrate using a 50 μL microsyringe as the reaction vessel, and the absolute configuration was assigned via qualitative determination of the fast reaction by thin-layer chromatography.

Nanomole-scale assignment of configuration for primary amines using a kinetic resolution strategy.

The absolute configurations of primary amines were assigned using a kinetic resolution strategy with Mioskowski's enantioselective 1-(R,R) and 2-(S,S) acylating agents. A simple mnemonic was developed to determine the configuration. A pseudoenantiomeric pair of reagents, 1-(R,R) and 2-(S,S)-d(3), was prepared and used to assay primary amines on a micromolar scale.

C2 hydroxyl group governs the difference in hydrolysis rates of methyl-α-D-glycero-D-guloseptanoside and methyl-β-D-glycero-D-guloseptanoside.

A computational investigation into the hydrolysis of two methyl septanosides, methyl-α-D-glycero-D-guloseptanoside and methyl-β-D-glycero-D-guloseptanoside was undertaken. These septanosides were chosen as model compounds for comparison to methyl pyranosides and allowed direct comparison of α versus β hydrolysis rates for a specific septanoside isomer. Results suggest that hydrolysis takes place without proceeding through a transition state, an observation that was suggested in previous computational studies on exocyclic bond cleavage of carbohydrates.