Toshio Miwa

C-glycopyranosides from the reaction of acetylated glycals with β-diketones

Acetylated glycals react with some β-dicarbonyl compounds in the presence of boron trifluoride or bis(benzonitrile)dichloropalladium to give C-glycopyranosides.

Reactions of dehydrobenzene—III : The reactions with substituted tropones and N-trichloroacetyltroponimine

Abstract The reactions of α-chloro-, α-bromo-, α-methoxy-, and α-hydroxy-tropones and N-trichloroacetyltroponimine with dehydrobenzene are described.

Analysis of traces of polycyclic aromatic hydrocarbons by adsorption on cobalt phthalocyanine and barium salts of sulphophthalocyanines followed by thermal desorption gas chromatograph

Abstract Small amounts of polycyclic aromatic hydrocarbons (PAHs) in aqueous solution were almost completely adsorbed on barium salts of copper (II) sulphophthalocyanines and cobalt (II) phthalocyanine, which were precipitated from the solution. Recoveries of the PAHs from the precipitates by thermal desorption gas chromatography were 71–95%. The method is useful for the concentration and analysis of medium molecular weight, thermally stable PAHs.

Synthesis by benzilic acid rearrangement of the 2-oxo-3-pyrroline dimeric alkaloid of Mercurialis leiocarpa

Abstract The 2-oxo-3-pyrroline dimer, 3,3′-bis(1,1′-dimethyl-2,2′-dioxo-4,4′-dimethoxy-5,5′-dihydroxy-5,5′-dimethoxycarbonyl-3-pyrroline), present in Mercurialis leiocarpa has been synthesized.

New ketone synthesis viaβ-hydroxy o-nitrophenyl selenoxides; a one-step synthesis of deoxy-keto sugars

β-Hydroxy o-nitrophenyl selenides and their O-alkyl or O-acyl derivatives were prepared and converted into ketones or the corresponding enol derivatives in satisfactory yields; these reactions were applied to the synthesis of sugar derivatives.

Cyclopentane-annelated pyranosides: a new approach to chiral iridoid synthesis

1-α-O-Methyl-loganin (1) was synthesised from methyl 2,3-anhydro-α-D-lyxopyranoside by cyclopentane annulation using the pyranose ring as the tetrahydrocoumalate skeleton.

Simple synthesis of methyl DL-desosaminide

A short route to DL-desosamine from the product of the condensation of 4-nitrobutan-2-ol with sodium glyoxylate is described.

Claisen rearrangement of hexenopyranoside allyl ethers: A new approach to α-branched-chain dicarbonyl sugars

Abstract The β-hydroxy phenylselenides prepared by cleavage of 2,3-anhydropyranosides with sodium phenylselenide were quantitatively transformed into the corresponding allyl ethers. Oxidation of the allyl ethers, followed by thermal elimination and rearrangement, gave C -allylhexosuloses in good yield. Rearrangement of ethers 10a and 10c was especially stereoselective, giving axially oriented C -allylhexosulose derivatives, which were readily epimerized to their equatorial isomers in quantitative yield. In the Claisen rearrangement of the crotyl ether 14c , the chirality of the sugar was transferred to the newly formed asymmetric carbon atom. This procedure provides a convenient method to convert an anhydro sugar into a C -allylhexosulose derivative.

Asymmetric Birch reduction of furoic acids

The Birch reduction of furoic acids in the presence of 1,2 : 5,6-di-O-isopropylidene-α-D-glucofuranose gave optically active dihydrofuroic acids.

Stereochemistry of the photochemical Berson-Willcott rearrangement of methyl 2,3-benzonorcaradien-7-ylacetate to methyl 2,3-benzobicyclo-[3.2.0]hepta-2,6-dien-4-ylacetate

The photochemical Berson-Willcott skeletal rearrangement of methyl 2,3-benzonorcaradien-7-ylacetate to methyl anti-2,3-benzobicyclo[3.2.0]hepta-2,6-dien-4-ylacetate was found to proceed with inversion of configuration at C-7.