Abstract:
The present invention has for its object to provide a method for producing an L-allysine acetal which involves a fewer steps and is efficient. This invention relates to method for producing an L-allysine acetal which comprises; converting a D,L-allysine acetal of the following general formula (1) (wherein R1 and R2 are the same or different, and each of them represents an alkyl group having 1 to 8 carbon atoms, or they combinedly form a ring and represent an alkylene group having 2 to 8 carbon atoms) to a mixture of a 2-oxo-6,6-dialkoxyhexanoic acid of the following general formula (2) (wherein R1 and R2 are as defined above) and an L-allysine acetal of the following general formula (3) (wherein R1 and R2 are as defined above) by reacting in the presence of an enzyme capable of stereoselective oxidative deamination of D-amino acids and; isolating said L-allysine acetal after said converting.
Abstract:
A shoe press belt for the shoe press of a paper making machine includes first and second resin layers and a base layer. Resin is coated and cured on the polished surface of a cylindrical mandrel to form the first resin layer endlessly. An inner layer of the base layer is formed by spirally winding a relatively narrower belt shaped mesh with warp threads running in the major direction of the belt and weft threads running perpendicular thereto, with the weft threads against the outer surface of the first resin layer, and without overlapping the end edges of the belt-shaped mesh. An outer layer of the base layer is formed by inserting the mandrel, with the first resin layer and the belt-shaped mesh layer applied, into a tubular mesh, and pulling the ends of the tubular mesh apart, so as to reduce its diameter and press it radially against the belt-shaped mesh layer. A second resin layer is then applied over the base layer and impregnates the base layer down to the outer surface of the first resin layer, so that the base layer is included within the second resin layer when the second resin layer is cured.
Abstract:
Processes for efficiently producing .alpha.-halo ketones, .alpha.-halohydrins and epoxides on an industrial scale. The prosesses include one for producing an .alpha.-halo ketone of general formula (3) by decarboxylating a product of reaction between a carboxilic acid derivative of general formula (1) and a metal enolate prepared from an .alpha.-haloacetic acid of general formula (2) or an acceptable salt thereof, one for producing an by reducing the .alpha.-halo ketone (3), and one for producing an epoxide (13) by treating the .alpha.-halohydrin (11) with a base to effect ring closure. The above prosesses are particularly suitable for producing optically active .alpha.-halo ketones, .alpha.-halohydrins and epoxides from the corresponding .alpha.-amino acid derivatives. ##STR1##
Abstract:
A fastening member 30 of a battery terminal 10 has a core wire covering member 32 formed by bending a pair of protecting members 32a which extend from the root portion of a wire barrel 31. The core wire covering member 32 is between the connecting portion 20 and the usual wire barrel portion 31, and is approximately rectangular when seen in cross-section. A clamp bolt 50 and nut 51 are tightened by means of a spanner or the like, thereby attaching the battery terminal 10 to a battery post P. The covering member 32 ensures that the end of the core wire or loose strands of the core wire do not interfere with the tightening operation or become caught on the operator's hand or on a tool. The wire covering members 33, 34 may include inspection apertures 33c, 34b.
Abstract:
A gas refining system for adsorbing a reducing gas includes a reduced gas stream, a section for adsorbing and removing sulfur-containing compounds in the reducing gas, an adsorbent which contacts the reduced gas stream, an oxygen-gas containing stream which enters the adsorbing and removing section, a calcium-compound containing stream, and a reactor which receives the above streams and allows for the adsorption of sulfur dioxide and precipitation of a gypsum compound.
Abstract:
A process for efficiently producing (S,S)-2-alkoxycyclohexanols in a single step by using (.+-.)-trans-2-alkoxycyclohexanols which are inexpensive and can be easily obtained. The process comprises treating a (.+-.)-trans-2-alkoxycyclohexanol with a hydrolase originating in a microorganism and being capable of esterifying stereospecifically the R-isomer in the presence of an acyl donor under such conditions that no hydrolysis occurs substantially to thereby give (S,S)-2-alkoxycyclohexanols and (R,R)-2-alkoxycyclohexanol carboxylate and then taking up the (S,S)-2-alkoxycyclohexanols.
Abstract:
The present invention has for its object to provide an efficient and economical method for producing an 3-amino-2-hydroxy-1-propanol derivative and an oxazolidinone derivative derived therefrom, both of which are of use as intermediates for the production of drugs including HIV protease inhibitors. The invention relates to a method for producing an 3-amino-2-hydroxy-1-propanol derivative of general formula (2) ##STR1## (wherein R.sup.1 represents alkyl, aralkyl or aryl; R.sup.2 and R.sup.3 independently represent hydrogen or an amino-protecting group, provided, however, that both R.sup.2 and R.sup.3 are not concurrently hydrogen) and an oxazolidinone derivative derived therefrom.
Abstract:
A process for producing optically active 1-halo-3-amino-4-phenyl-2-butanol derivatives from optically active 1-halo-3-amino-4-phenyl-2-butanone derivatives stereoselectively in a high yield by bringing the butanone derivatives into contact with microorganisms.
Abstract:
A female connector housing 11 has a locking arm 30 integrally moulded thereon, the locking arm 30 having a fitting projection 31. A male connector housing 21 has a fitting hole 24 formed on hood member 22 thereof. Two slots 34 are formed on either side of the fitting projection 31 so as to extend along the longitudinal direction of the locking arm 30. The locking arm 30 is thus partitioned into a fitting arm member 35 which includes the fitting projection 31, and two supporting arm members 36 which are formed on both sides thereof. The foot members 36a of the supporting arm members 36 are thicker than the foot member 35a of the fitting arm member 35, and thus the engagement load of the arm 30 is large, but the projection 35a is nevertheless relatively easy to disengage.
Abstract:
A die for press-molding glass optical elements which can press-mold glass optical elements having high melting points and various shapes repeatedly, which includes a base material having high strength on which a cutting layer having heat resistance and free cutting machinability is formed. After cutting the cutting layer into the desired shape with high accuracy, the die is coated with a surface protective film.