Simple synthesis of beta-D-glycopyranosides using beta-glycosidase from almonds

Enzymatic glycosidation of twenty-one kinds of alcohols (n-hepanol, n-octanol, 2-phenylethanol, 3-phenylpropanol, 4-phenylbutanol, 5-phenylpentanol, 6-phenylhexanol, furfury alcohol, 2-pyridinemethanol, isobutanol, isopentanol, p-methoxycinnamylalcohol) including secondary alcohols (isopropanol, cyclohexanol, 1-phenylethanol) and 1,omega-alkanediols (1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol), salicyl alcohol and 4-nitrophenyl beta-D-glucopyranoside (5) using beta-glucosidase from almonds stereoselectively gave the corresponding beta-D-glucopyranosides in moderate yield.     

Synthesis of methyl 1-O-(4-hydroxymethamphetaminyl)-alpha-D-glucopyranouronate

For the purpose of the direct characterization of the intact conjugated form in the urine of a methamphetamine (MA) abuser, 4-hydroxymethamphetamine (4-OHMA) glucuronate, corresponding to one of the metabolites of MA, was synthesized from the commercially available methyl 4-hydroxyphenylacetate.     

New Fluorophores Based on Non-Cyclic Crown Ethers for Alkali and Alkaline Earth Metal Cation

Recent advances regarding podand derivatives which are non-cyclic crown ethers incorporating functional groups have been reviewed. Particular attention has been paid to fluorophore appended non-cyclic crown ethers as sensors for cation detection. Their complexation behavior with alkali and alkaline earth cations and interactions between their terminal groups is also discussed in detail.     

Solvolysis of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoate derivatives

The solvolysis reaction of (4,5)-anti-4-aryl-5-tosyloxy-2(E)-hexenoates 4a-k gave (4,5)-anti-4-aryl-5-hydroxy-2(E)-hexenoates 2a-k and (4,5)-anti-5-aryl-4-hydroxy-2(E)-hexenoates 5a-k along with the complete inversion. This 1,2-aryl migration was induced by treatment with heating in water-saturated nitromethane. On the basis of the substituent effect on the aromatic ring, this 1,2-aryl migration is thought to proceed via the sigma-bridged phenonium ion. The product selectivity between 2a-k and 5a-k was found to be subtly governed by the substituent and substitution pattern in the aromatic ring of the substrates 4a-k.     

Development of chiral (S)-prolinol-derived ligands for palladium-catalyzed asymmetric allylic alkylation: effect of a siloxymethyl group on the pyrrolidine backbone

A series of novel chiral aminophosphine ligands are designed and readily prepared from (S)-prolinol. The reactivity and selectivity in the palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with a dimethyl malonate-BSA-LiOAc system using these chiral ligands are evaluated, and the structural elucidation of ligands and palladium complex is also conducted. Moreover, a series of trialkylsilylated chiral aminophosphine ligands are prepared and applied to palladium-catalyzed asymmetric allylic alkylation (up to 98% ee).