N-Benzyl-L-valine

A soln. of L-valine in 2 N NaOH vigorously stirred, treated with benzaldehyde, after 15-20 min. NaBH4 added below 15°, stirring continued 0.5 hr., the treatment with benzaldehyde and NaBH4 repeated, finally stirred 2 hrs. N-benzyl-L-valine (Y 86%) heated 1.5 hrs. on a steam bath with formic acid and 38-40%-formaldehyde soln. N-benzyl-N-methyl-L-valine (Y 92%) dissolved in 90%-acetic acid, and hydrogenated with 5%-Pd-on-carbon N-methyl-L-valine (Y ... 

C24H38CUN2O6, (N-Benzyl-D-valinato)(N-benzyl-L-valinato)copper(II) dihydrate (blue isomer), 41B, 1039 C2ftH38CUN2O7, Bis(N-benzyl-L-valine)copper(II) trihydrate, 42B, 806 C2 6H31CIMO2N2O4S2, Hydrogendi (bis-TT-cyclopentadienyD-L-cysteinato-molybdenurndV) chloride, 38B, 895... 

A template polymer complex, which incorporates N-benzyl-D-valine with almost 100 % stereospecificity, has been synthesized by copolymerization of A-P2-[Co (R,R )-A, /V -bis(4-(vinylbenzyloxy)salicylidene]-l,2-diaminocyclohexane -(A-benzyl-D-valine)], styrene, and divinylbenzene, followed by dissociation of the coordinated amino acid 115). 

N-[p-(o-1 H-T etrazol-5-ylphenyl)benzyl]-N-valeryl-L-valine. CGP-48933 Diovan Valsartan. A non-peptide angioten-sin II AT1-receptor antagonist. Used as an anti-hypertensive agenl Crystals mp = 116-117°. Ciba-Geigy Corp. 

In addition to the proline polymers, polymers containing N-carboxymethyl-L-valine (Snyder et al., 1972), A -()3-hydroxyethyl)-D-propylenediaminotetraacetic acid (Humbel et al., 1970 Bemauer et al., 1971), L-histidine (Guette et al., 1978), and iV-benzyl-L-leucine (Tsuchida et al., 1976) have been used to separate racemates of amines and amino acids. 

XXVII Inden BFj-Atherat + optiscli aktive Co-katalysatorcn (1-a-Methyl-benzyl-alkohol, Tosyl-L-Valin, Campher) in n-Hexan odcr CHClj bei 0° bzw. -SO C disyndiotaktisch (84,104)... 

The synthesis of the 10-methoxytetracyclic ketone 353 (Scheme 26) started from the readily available 3-methyl-5-methoxyindole 355, which after Boc protection, was brominated, and then condensed with the anion of the Schollkopf auxiliary 356 (from l-valine). Removal of the Boc-protecting group, followed in succession by A -methylation and hydrolysis, gave the required A -methyl-5-methoxy-D-tryptophan ethyl ester 357, which was then transformed into the key 10-methoxytetracyclic ketone 353, via N-benzylation, Pictet-Spengler condensation, and Dieckmann cyclization. Subsequent N-alkylation by the vinyl iodide 358 followed by Pd-catalyzed (enolate-driven)... 

Various L-a-amino acids (glycine, L-alanine, L-valine, L-aspartic acid, L-isoleucine, histidine) have been converted into the corresponding N-carboxyanhydrides by N-protection with benzyl chloroformate and further reaction with SOCI2 [846-853]. 

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