L-tyrosine methyl ester

Solution-phase enantioselective synthesis of 437 and 438 thus achieved was also translated into solid-phase synthesis <2002TL8981>. The oxazolidinone 441 prepared from L-tyrosine methyl ester via 440 was attached to Merrifield resin to produce 442. Resin-bound 442 was converted to 443 (Scheme 98). 

Table 12.7 Yields of a-chymotrypsin-catalyzed peptide synthesis in water and ice using maleoyl-L-tyrosine methyl ester as acyl donor and various peptides, amino acid amides, and amino acids as nucleophiles (Schuster, 1990).

Similarly, the norbelladine derivative 489, prepared from L-tyrosine methyl ester and isovaniiine, was oxidized with PhI(OCOCF3)2 in trifiuoroethanol (TFE) at —40°C to afford in 64% yield an intramolecular coupled product 490. This is known as the key... 

Calcium, magnesium and strontium salts accelerated the a-chymotrypsin-catalysed transesterification of A -acetyl-L-tyrosine methyl ester (202) to a modest extent (2-6-fold). ... 

Z-Gln-Tyr-OMe[l,-Tyrosine, A, -[A72-[(phenylmethoxy)-carbonyI]-L-glutammyl]-, methyl ester] A 75%... 

RN 2544-09-4 MF C,2H,7N04 MW 239.27 EINECS 219-821-2 CN 3-hydroxy-a-methyl-L-tyrosine ethyl ester... 

I vnmetiial Proved me. 1 1 llieiiliculion ul l- inoc-tyrosine methyl ester with a di.ilknwben/v I alcohol linker 117u ... 

In contrast to the rutelines, the melolonthine scarabs generally use terpenoid-and amino acid-derived pheromones (reviewed in Leal, 1999). For example, the female large black chafer, Holotrichia parallela Motschulsky, produces methyl (2.S, 3. Sj - 2 - am ino-3-methy lpcn tanoatc (L-isoleucine methyl ester) as an amino acid-derived sex pheromone (Leal et al., 1992 Leal, 1997). There is no direct evidence that the chafer beetles or any other Coleoptera use the shikimic acid pathway for de novo pheromone biosynthesis, but some scarabs and scolytids (see section 6.6.4.2) may convert amino acids such as tyrosine, phenylalanine, or tryptophan to aromatic pheromone components (Leal, 1997,1999). In another melolonthine species, the female grass grab beetle, Costelytra zealandica (White), the phenol sex pheromone is produced by symbiotic bacteria (Henzell and Lowe, 1970 Hoyt et al. 1971). 

C11H12CIN04 N-(2-chloroacetyl)-L-tyrosine 1145-56-8 25.00 1.3161 2 21990 C11H13N03 N-benzoyl-L-alanine methyl ester 7244-67-9 25.00 1.1676 2... 

Figure 5. L-Tyrosine derivatives (a) N-formyl-L-tyr, anionic form at moderate pH levels (b) L-tyr methyl ester, cationic form at moderate pH levels.

L-Tyrosine hydrochloride L-Cysteine methyl ester hydrochloride Quinuclidine hydrochloride p-Dichlorobenzene... 

Chiral intermediates for the synthesis of (-)-anisomycin (1) and (+)-anisomycin (anti-1) (153), (R)-2-(p-methoxyphenyl)methyl-2,5-dihydro-pyrrole (142) and its (S)-isomer (+)-187, have been efficiently synthesized from D-tyrosine and L-tyrosine, respectively (Scheme 20) [28]. D-tyrosine was converted to 0-methyl D-tyrosine methyl ester (182) [72-75] which was treated with di-tert-butyl dicarbonate to protect the amino group. Subsequent reduction of the ester group with sodium borohydride in the presence of lithium chloride furnished the alcohol 183. Swern oxidation of 183 followed by chain extension with the anion derived from bis(2,2,2-trifluoroethyl)(ethoxycarbonylmethyl)-phosphonate afforded (Z)-Q ,/0-unsaturated ester (184), which was used immediately without purification to avoid or minimize any possible racemization of the chiral center. Reduction of the ester group of 184 with diisobutylaluminium hydride afforded the alcohol 185 which after mesylation followed by intramolecular cyclization gave the desired 2,5-dihydropyrrole derivative 186. Removal of the tert-butyloxycarbonyl group was achieved by treatment with trifuoroacetic acid to give (-)-142 in 62% overall yield from 182. The (S)-2,5-dihydropyrrole (-l-)-187 was also prepared in the same manner starting from L-tyrosine. Since (-l-)-187 had been transformed into (-l-)-anisomycin (anti-1) (153), (-)-142 could also be transformed to the (-)-anisomycin (1) [26,66]. 

In the case of monomer 7 (60)a 4-vinylphenyl-boronic acid is bound to the two hydroxyl groups of L-DOPA methyl estec In addition, 5-vinylsalicylaldehyde ( ) is linked to the amino-group through an azomethine-bond. Polymerization under the usual conditions and splitting off the template, L-DOPA methyl ester, yielded a polymer that showed a separation factor a = 1.98 for the solution of the racemate of the template. The same polymer did not resolve the racemate of tyrosine methyl ester or... 

An arginine e r, p-tosyl-L-arginine methyl ester (TAMe), inhibited the function of Cls to cleave C2 (Stroud et al., 1965), but a tyrosine ester, V-acetyltyrosine ethyl ester (ATEe), only slightly inhibited the cleavage of C4 by Cl (Shimada and Tamura, 1972). These results suggested that the chymotrypsinlike specificity of Cls for synthetic esters bears no relation to the proteolytic function of Cls. 

---