O methyl ester

In a one-pot synthesis of thioethers, starting from potassium 0-alkyl dithiocarbonate [36], the base hydrolyses of the intermediate dialkyl ester, and subsequent nucleophilic substitution reaction by the released thiolate anion upon the unhydrolysed 0,5-dialkyl ester produces the symmetrical thioether. Yields from the O-methyl ester tend to be poor, but are improved if cyclohexane is used as the solvent in the hydrolysis step (Table 4.13). In the alternative route from the 5,5-dialkyl dithiocarbonates, hydrolysis of the ester in the presence of an alkylating agent leads to the unsymmetrical thioether [39] (Table 4.14). The slow release of the thiolate anions in both reactions makes the procedure socially more acceptable and obviates losses by oxidation. 

Figure 25. Trace enantiomer analysis of L-aspartic acid (obtained by enzymatic amination of fumarate with L-aspartase and determined as the A -trifluoroacetyl-O-methyl ester) on i.-Chirasil-Val31 [20 mx0.25 mm (i.d.) glass capillary column, 90 CC, 0.4 bar hydrogen] with detection by GLC MS selected ion monitoring (mj 198.1) and multiscanning chromatography (MSC, 8 scans)186.

The assigned structures are confirmed by relating them chemically to GAs or GA-derivatives of known structure. For example, GAl o methyl ester was converted to the known compound, deoxy GA methyl ester (j+3), by formation of the toluene-p-sulfonate and treatment of this with boiling collidine (1-2). 

It has been reported <1998CC2315> that a similar [2+2] intramolecular cyclization of (2-cyclohex-l-enyl-2-methyl-propionyl)phenyl-thiocarbamic acid O-methyl ester leads to the formation of tricyclic thietane in 85% yield (Table 2). 

Naturally, reactions are especially interesting to us if the products obtained are not readily accessible by the methods of classic organic chemistry but are easily preparable with our complexes. We found one such example upon treatment of pentacarbonyl[methoxy(aryl)carbene]chrom-ium(O) complexes with oxygen, sulfur, or selenium (76). In this way one obtains conveniently the corresponding methyl esters of arylcarboxylic acids and the O-methyl esters of arylthio- as well as arylselenocarboxylic acids this seems to us to be synthetically useful in the last two cases ... 

Methyl ethers and esters are also found as volatile constituents in a wide range of flowers and fragrant herbs. For example, methyleugenol is found in the essential oil of herbs such as sweet basil and in the floral headspace of a wide range of flowers.7"10 Defense compounds and phytoalexins are commonly O-methylated as well. These compounds include the 3 -O-methylated form of the flavonoid quercetin as well as the 7-O-methyl ester of the flavone apigenin (Fig. ll.l).11,12 While not within the scope of this paper, it should be noted that protein O-methylation is common.13,14 One interesting protein modification known to occur in Arabidopsis thaliana is the a-carboxyl methylation of prenylated proteins.15 This modification has been shown in mammals and yeast to be important in protein targeting and membrane association.16,17... 

An orf/io-directed lithiation allows the conversion of 25 to aryl iodide 40. Reductive ether formation of aldehyde 40 with crotyl alcohol yields compound 41. Intramolecular Heck reaction of 41 affords a mixture of the olefins 42 and 43. The undesired alkene 42 can be isomer-ized quantitatively to the desired enol ether 43 with Wilkinson s catalyst. Sharpless dihydroxylation ee 94 %) of the enol ether 43 provides lactol 44, which is oxidized directly to lactone 45. Finally, the pyridone-O-methyl ester is cleaved under acid conditions (45 — 7). 

Thiokohlensaure -imid-O-methyl-ester-S-(4-methyl-phenyl-ester) E4, 572 (Ar-SCN + R-OH)... 

Thiocarbamidsdure N-(Morpholino-carbonyI)-N-phenyl- -O-methyl-ester E4, 1047 [Cl - N(Ar) -C0-NR2]... 

SYNS AI3-25722 CARBONIC ACID, DITHIODI-, o,o -DIMETHYL S,S -(2,3-QUINOXALINEDIYL) ESTER CARBONOTHIOIC ACID, S,S -2,3-QUINOXALINEDIYL o,o -DIMETHYL ESTER CARBONIC ACID, THia, o,o -DIMETHYL S,S -2,3-QUINOXALINEDIYL ESTER CARBONIC ACID, THIO-, o-METHYL ESTER, S,S-DIESTERMTH2,3-QUINOXALINEDITHIOL o,o -DIMETHYL S,S -2,3-QUINOXALINEDIYL THIOCARBONATE SAS2185... 

PHENDLPHENOL, SODIUM SALT see BGJ750 a-PHENYLPHEN YLACETONTTRILE see D X200 PHENYLPHOSPHINE see PF 250 PHENYLPHOSPHINE DICHLORIDE see DGE400 PHENYLPHOSPHONOTHIOIC ACID 0-(4-BROMO-2,5-BROMO-2,5-DICHLOROPHENYL) O-METHYL ESTER see LENOOO... 

Dimayuga et al. (1991) reported activity of camosol against B. subtilis and Candida albicans, and supported results on S. aureus and E. coli. The authors used 4 mg per disc. Significant activity was also found for camosic acid and its 12-O-methyl ester to inhibit S. aureus. The inhibitive action is due to the inhibition of the nucleic acid biosynthesis pathway, as camosic acid prevents the incorporation of thymidine and uridine into the DNA and RNA of S. aureus (Wagner, 1993). 

Amphetamines e.g. 2,S-dimethoxy-4-bromoamphetamine [S] /O Methyl esters of fatty acids [6] ... 

The binaphthyl phosphate ester (127) has been proposed as a resolving agent and its absolute configuration determined. A successful resolution procedure for the O-methyl ester of t-butylphosphonothioic acid has been reported. N.m.r. will distinguish between the diastereo-isomers of (128) and between the diastereoisomeric salts of (129) with o -phenylethylamine. ... 

A retro-Pishschimuka reaction has recently been reported, in which the quaternary salts from the (R)-(+)-5 -methyl phosphinothioates (115 R = Me or Bu ) and methyl triflate (Scheme 23) are treated with NaSH, which results in the formation of the isomeric O-methyl esters of unchanged configuration although with some loss of optical purity ... 

CAS 606-45-1 EINECS/ELINCS 210-118-6 Synonyms o-Anisic acid, methyl ester Benzoic acid, 2-methoxy-, methyl ester Dimethyl salicylate 2-Methoxybenzoic acid methyl ester o-Methoxybenzoic acid methyl ester o-Methoxy methyl benzoate Methyl 2-methoxybenzoate Methyl o-methoxybenzoate Methyl salicylate o-methyl ester Empirical C9H10O3... 

Methyl salicylate o-methyl ester. See Methyl o-anisate... 

C9H10OS 4-methyl-thiobenzoic acid O-methyl ester 5977-80-0... 

C9H10OS phenyl-thioacetic acid O-methyl ester 5873-85-8... 

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