2-Hydroxy-3-chlorophenyl esters

Ethane, 1,1 -thiobis[2-chloro- Chlorobenzilate Benzeneacetic acid,4-chloro-.alpha.-(4-chlorophenyl)-.alpha.-hydroxy-,ethyl ester 2-Chloroacetophenone... 

Metabolism of the 2,S -isomers proceeds sequentially hydroxylation at the phenoxy group, hydrolysis of the cyano group, and cleavage of the ester linkage (Coats et al. 1989). Fenvalerate and the IS-isomers yield two ester metabolites in feces from hydroxylation at the 4 - and 2 -phenoxy positions. Other significant metabolites were 3-phenoxybenzoic acid and its hydroxy derivatives from the alcohol moiety, 3-(4-chlorophenyl) isovaleric acid and its hydroxy derivatives from the acid moiety, and thiocyanate and carbon dioxide from the cyano moiety (Ohkawa et al. 1979). A slow elimination rate characterizes fenvalerate and other a-cyano pyrethroids when compared with... 

Chlorophenyl)glutarate monoethyl ester 87 was reduced to hydroxy acid and subsequently cyclized to afford lactone 88. This was further submitted to reduction with diisobutylaluminium hydride to provide lactol followed by Homer-Emmons reaction, which resulted in the formation of hydroxy ester product 89 in good yield. The alcohol was protected as silyl ether and the double bond in 89 was reduced with magnesium powder in methanol to provide methyl ester 90. The hydrolysis to the acid and condensation of the acid chloride with Evans s chiral auxiliary provided product 91, which was further converted to titanium enolate on reaction with TiCI. This was submitted to enolate-imine condensation in the presence of amine to afford 92. The silylation of the 92 with N, O-bis(trimethylsilyl) acetamide followed by treatment with tetrabutylammonium fluoride resulted in cyclization to form the azetidin-2-one ring and subsequently hydrolysis provided 93. This product was converted to bromide analog, which on treatment with LDA underwent intramolecular cyclization to afford the cholesterol absorption inhibitor spiro-(3-lactam (+)-SCH 54016 94. 

Racemic resolution of a-hydroxy esters was achieved with Pseudomonas cepacia lipase (PCL) and a ruthenium catalyst (for a list, see Figure 18.13) as well as 4-chlorophenyl acetate as an acyl donor in cyclohexane, with high yields and excellent enantiomeric excesses (Huerta, 2000) (Figure 18.14). Combining dynamic kinetic resolution with an aldol reaction yielded jS-hydroxy ester derivatives in very high enantiomeric excesses (< 99% e.e.) in a one-pot synthesis (Huerta, 2001). 

Chlorobenzilate or ethyl 2-hydroxy-2,2-di-(p-chlorophenyl)-acetate is a chlorinated aromatic a-hydroxy ester. It has an empirical formula of C gH C Og and a molecular weight of 325.18. 

Indeed, in a patent held by the Dow Chemical Company(1)it is observed that epichlorohydrin (or other suitable 1,2-epoxide) is required in order to obtain high yields of glycidyl esters from 2-hydroxy-3-chlorophenyl esters. A mechanism involving transepoxidation was proposed (Fig. 17). 

The Knoevenagel and Wittig type reactions have been used for the creation of the 6-bond. The condensation of octadecanal with methyl p-(chlorophenyl)sulfinyl acetate in the presence of piperidine afforded the corresponding acetate after acetylation of the hydroxy group which, after subsequent molibdenum-catalyzed elimination, gives the dienic ester as a 4 1 E,E E,Z mixture. After final amidation, the amide trichonine (13) [40] is obtained (Scheme 2). A similar strategy has been used for the synthesis of piperovatine (21) with total E,E-stereoselectivity [41]. 

D-lyxo-l,2,3-trihydroxybutyl)-p-D-xylopyranosid-4-yl)-2-phenyl-, hexaacetate ester -4-methanol, a-t5-(acetyloxy)-l,3-doxan-4-yl]-2-phenyl-, acetate ester, [4S-[4o(S ), 5a]]--4-methanol, a -(aminometyl)-2-phenyl--4-methanol, 2-(4-bromo-3-chlorophenyl)--4-methanol, 2-(4-bromo-3-methylphenyl)--4-methanol, 2-(4-bromophenyl)--4-methanol, 2-(3-chlorophenyl)--4-methanol, 2-(4-chlorophenyl)--4-methanol, a -(ethylaminomethyl)-2-phenyl--4-methanol, a -(5-hydroxy-1,3-dioxan-4-yl)-2-phenyl-, [4S-[4a(S ), 5o]]-... 

Synonyms ethyl 2-hydroxy-2,2-bis(4-chloro-phenyl)acetate 4,4 -dichlorobenzilic acid ethyl ester 4-chloro-a-(4-chlorophenyl)-a-hydroxybenzeneacetic acid ethyl ester 4,4 -dichlorobenzilate... 

Synonyms Acar Acaraben Acaraben 4E Akar Akar 50 Akar 338 Benzilan Benz-o-chlor Chlorbenzilat Chlorbenzilate Chlorobenzylate Compound 338 4,4 -Dichloroben-zilate 4,4 -Dichlorobenzilic acid ethyl ester ENT 18596 Ethyl 4-chloro-a-(4-chlorophe-nyl) -a-hydroxybenzene acetate Ethyl-4,4-dichlorobenzilate Ethyl-p,/> -dichlorobenzi-late Ethyl-4,4 -dichlorodiphenyl glycollate Ethyl-p,y-dichlorodiphenyl glycollate Ethyl-2-hydroxy-2,2-bis(4-chlorophenyl)acetate Folbex Folbex smoke-strips G 338 G 23,992 Geigy 338 Kop-mite NCI-C00408 NCI-C60413 RCRA waste number U038. 

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