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The reversal phenomenon of enantioface selectivity in the asymmetric addition of diisopropylzinc (II) to aromatic aldehydes (I) and (IV) is observed by mixing two chiral β-amino alcohol catalysts.

Optically active β-lactams were obtained conveniently by lipase-catalyzed enantioselective hydrolysis of 1-acyloxymethyl-2-azetidinones and esterification of 1-hydroxymethyl-3, 3-dimethyl-2-azetidinone with vinyl acetate in organic solvent.

Anodic oxidations of 4-trimethylsilylazetidin-2-one and 1-benzyl-4-trimethylsilylazetidin-2-one in the presence of alcohols or acetic acid regioselectively provide the corresponding 4-oxyazetidin-2-ones in good yields.

Optically active β-lactams were synthesized by lipase-catalyzed kinetic resolution using the enantioselective hydrolysis of N-acyloxymethyl β-lactams (3) in an organic solvent and the transesterification of N-hydroxymethyl β-lactams (2) with vinyl acetate. A variety of highly optically pure β-lactams (2 and 3) possessing some substituents at the 3, 4, or both positions were obtained and the optically active N-hydroxymethyl β-lactams prepared were converted into useful N-unsubstituted ones without racemization.

A process consisting of the deposition of amorphous silicon at low temperatures and subsequent annealing has been proposed for fabricating a boron-doped polycrystalline silicon film with a low resistivity. This process realized large grain growth up to 3 to 5 μm, leading to a low resistivity of 1.4 mΩ.cm, which one-half to about one-third compared with that of direct deposited boron doped polysilicon. In addition to this, extremely low deposition temperature (∼350 o C) using a Si 2 H 6 /B 2 H 6 mixture attained uniform boron concentration across the wafers

Trachyspic acid, a new metabolite that inhibited heparanase, was isolated from the culture broth of Talaromyces trachyspermus SANK 12191. Its structure was deduced from NMR spectral analyses and chemical reactions as a tricarboxylic acid derivative containing a spiroketal. The IC50 value of trachyspic acid against heparanase was 36 microM.

Summary Some novel 2-methyl-3-aminopropiophenones were synthesized and their centrally acting muscle relaxant activities were evaluated for an inhibitory effect on the flexor reflex in rats. The structure-activity relationships are discussed. In this series, 2-methyl-3-pyrrolidino-1-(4-trifluoromethylphenyl)-propan-1-one ( 28 ) showed significant centrally acting muscle relaxant activity. In addition, the activities of each enantiomer ( 28 -( S ) and ( R ) were studied along with their acute toxicities. Compound 28 -( R ) was found to exhibit more potent activity and weaker acute toxicity than 28 -( S ). Accordingly, compound 28 -( R ) (NK433) is under development as a novel centrally acting muscle relaxant.

A simple procedure has been developed for the synthesis of α-glycosyl cyanides: reactions of O-benzylated ethyl 1-thio-glycosides of l -fucose and d -glucose, with TMSCN and MeOTF in ether exclusively gave the corresponding α-glycosyl cyanides in good yields.

The reaction of 6-amino-2, 3-dimethylquinoxaline (1) with acetaldehyde in ethanol proceeded at refluxing temperature to give 10-ethoxy-2, 3, 8-trimethyl-7, 8, 9, 10-tetrahydropyrido[3, 2-f]quinoxaline (2), which was converted to 2, 3, 8-trimethylpyrido[3, 2-f]quinoxaline (4) and 2, 3, 8-trimethyl-7, 8, 9, 10-tetrahydropyrido[3, 2-f]quinoxaline (5) in an acidic medium. Crotonaldehyde also reacted smoothly at room temperature with 1 to afford several pyrido[3, 2-f]quinoxaline derivatives along with 4 and 5.

Treatment of CpFe(CO)2SiR3 (R3 = (pTol)2H, (pTol)2Me, MePh(1-Nap); 1-Nap = 1-naphthyl) with LiAlH4 in ether or THF at room temperature gave CH3SiR3 as a major product in moderate to high yield. The labeling experiments using LiAlD4 and CpFe(13CO)2SiR(pTol)2 (R = H, Me) proved unambiguously that the carbonyl ligand is reduced with LiAlH4 and coupled with the silyl group to give the methylsilane.

The combined use of aluminum tris(2,6-diphenylphenoxide) (ATPH) and lithium 2,2,6,6-tetramethylpiperidide (LTMP) has proven to be effective for the mixed crossed aldol condensation between conjugated esters and various aldehydes. An example is shown in Equation (1).

o-Quinodimethanes, generated by the Diels-Alder reactions of benzopyranylidenetungsten(0) complexes with electron-rich dienes, further undergo intramolecular cyclizations to afford novel polycyclic compounds.