Abstract: Catalytic asymmetric hydrogenation of the Z geometric isomer of a compound of the formula ##STR1## wherein at least one of R and R.sup.1 represents hydrogen and the other represents hydrogen, lower alkyl or aryl; R.sup.2 represents ##STR2## wherein R.sup.4 and R.sup.5 each independently represent hydrogen, lower alkyl or aryl, R.sup.6 represents hydrogen, lower alkyl, aryl or an alkali metal; and R.sup.3 represents ##STR3## wherein R.sup.7 and R.sup.8 each independently represent lower alkyl or aryl; provided that, when R.sup.3 is ##STR4## R.sup.2 is --CN, in the presence of a homogeneous, coordination complex catalyst comprising rhodium, iridium or ruthenium in combination with an optically active bis phosphine ligand provides an outstanding level of optical purity.

Abstract: There is described an improved process for the separation and recovery of L-phenylalanine and L-aspartic acid from sidestreams resulting from the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester. It has been found that superior separation is obtained by combining one or more of the mother liquor and wash solutions formed during the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester, hydrolyzing same to afford the hydrohalide salts of L-aspartic acid and L-phenylalanine, acidifying the hydrolysis solution to precipitate the hydrohalide salt of L-phenylalanine, separating the hydrohalide salt of L-phenylalanine, dissolving it in water and adjusting the pH of the solution to the isoelectric point of L-phenylalanine, thus affording pure L-phenylalanine, and thereafter adjusting the pH of the solution after separation of the L-phenylalanine hydrohalide to the isoelectric point of L-aspartic acid to precipitate L-aspartic acid.

Abstract: Stabilized amorphous calcium carbonate which is useful as a carbonate factor in effervescent compositions. Process for preparing stabilized amorphous calcium carbonate and compositions containing stabilized amorphous calcium carbonate.

Abstract: Catalytic asymmetric hydrogenation of a compound of the formula ##STR1## wherein R, R.sup.1 and R.sup.2 each independently represent hydrogen, substituted or unsubstituted alkyl having from 1 to 5 carbon atoms or substituted or unsubstituted aryl, and R.sup.3 represents substituted or unsubstituted alkyl having from 1 to 5 carbon atoms or substituted or unsubstituted aryl, provided that, if only one of R and R.sup.1 is hydrogen the Z geometric isomer is hydrogenated, in the presence of a homogeneous, coordination complex catalyst comprising rhodium, iridium or ruthenium in combination with an optically active bis phosphine ligand provides an excellent level of optical purity.

Abstract: A process for the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester wherein .alpha.-L-aspartyl-L-phenylalanine is contacted with a reaction medium comprising water, methanol and a hydrogen halide to form a solid hydrogen halide salt of .alpha.-L-aspartyl-L-phenylalanine methyl ester which can be separated and converted to .alpha.-L-aspartyl-L-phenylalanine methyl ester.

Abstract: A process which comprises contacting alkyl esters of .alpha.-L-aspartyl-L-phenylalanine with an aqueous solution containing barium ions, at a reaction pH greater than 7, to form .alpha.-L-aspartyl-L-phenylalanine.

Abstract: A process for the preparation of .alpha.-L-aspartyl-L-phenylalanine alkyl esters wherein L-phenylalanine is reacted with N-protected-L-aspartic anhydride, the resulting product is treated to yield .alpha.-L-aspartyl-L-phenylalanine which is esterified with an alkanol to yield an .alpha.-L-aspartyl-L-phenylalanine alkyl ester which is recovered.Novel precursors for .alpha.-L-aspartyl-L-phenylalanine alkyl esters are prepared in the process of this invention.