Dl-ALLOTHREONINE

A mixture of DL-threonine and DL-allothreonine was prepared by the hydrogenation of ethyl diazoacetoacetate over paltinum oxide in 70% ethanol containing sulfuric acid (eq. 9.90). 2,4-Dimethylpyrrole-3,5-dicarboxylic acid diethyl ester was also obtained as a byproduct. 

Addition tube, 20, 21 Alanine, /3-(3,4-dihydroxyphenyl)-N-METHYL-, 22, 89, 91 Alcoholic hydrochloric acid, 22, 77, 83 standardization, 22, 80 Alcoholysis, 20, 67 Aldehyde synthesis, 20, 14 from acid chlorides by Rosenmund reaction, 21, 84, 87, 88, 110 Alkylation of thiourea, 22, 59 Alkylchlororesorcinols, 20, 59 Alkylene bromide, 20, 24 S-Alkylthiuronium halides, 22, 60 dl-ALLOTHREONINE, 20, 10 ... 

See Table XIV. Reference chemical-shift for O is that measured for DL-allothreonine (17.15 p.p.m.). 

Alkylchlororesorcinols, 20, 59 Alkylene bromide, 20, 24 Alkylidenecyanoacetic esters, 25,48 Alkyl phenyl selenides, 24, 91 S-Alkylthiuronium halides, 22, 60 dl-ALLOTHREONINE, 20, 104 Alloxan, 23, 3... 

They found, also, that DL-allothreonine is more readily transformed than DL-threonine—a result which has been confirmed in the intact animal in the author s laboratory. ... 

A mixture of frans-a, -epoxybutyric acid, benzylamine, and water refluxed 2 hrs. N-benzyl-DL-allothreonine. Y almost 100%.—The ring opening occurs with inversion of configuration trans- give erythro-isomers exclusively, whereas cis- give fhreo-isomers. F. e. s. Y. Liwschitz, Y. Rabinsohn, and D. Perera, Soc. 1962, 1116. 

C8Hi7BrN203, D-Leucylglycine hydrobromide, 31B, 190 34B, 267 C8H17N3O2, N(a)-Acetyl-aza-a -homo-L-valine methylamide, 42B, 359 C8Hi9BrN206, DL-Allothreonine hydrobromide, 41B, 541 C8H20CI2N2O5S2f L-Cystine dimethyl ester dihydrochloride monohydrate, 41B, 540... 

The mammalian enzymes, L-serine dehydrase and L-threonine dehy-drase, have been separated and purified from sheep liver by Sayre and Greenberg (230). L-Serine dehydrase was found to be specific for L-serine. No activity was observed with the n-isomer or with d- or L-threonine. L-Threonine dehydrase was active with L-threonine, but not the D-isomer, and to a slight extent with L-serine. It has not been established whether L-serine is a true substrate for L-threonine dehydrase or whether the enzyme preparation is still contaminated with the L-serine dehydrase. Neither enzjrme was active with DL-allothreonine, DL-homocjrsteine, DL-cysteine, or jS-phenylserine. 

C4H9NO3, L(S)-Threonine, 13, 488 40B, 434 C HjNOa, L-Allothreonine, 41B, 525 CftHgNOa, L-Threonine - L-allothreonine, 41B, 526 C4H9NO3S, (+)-S-Methyl-L-cysteine sulfoxide, 27, 765 CftH9NOsS, DL Homocysteic acid, 43B, 589... 

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