Mercury salt methyl ester

Subsequent dehydrohalogenation afforded exclusively the desired (Z)-olefin of the PGI2 methyl ester. Conversion to the sodium salt was achieved by treatment with sodium hydroxide. The sodium salt is crystalline and, when protected from atmospheric moisture and carbon dioxide, is indefinitely stable. A variation of this synthesis started with a C-5 acetylenic PGF derivative and used a mercury salt cataly2ed cyclization reaction (219). Although natural PGI has not been identified, the syntheses of both (6R)- and (65)-PGl2, [62777-90-6] and [62770-60-7], respectively, have been described, as has that of PGI3 (104,216). 

Its Mercury salt, HgfCj N302)2- sulfur-yel crysts (from eth), mp 123° (dec), sol in hot eth was obtd by reaction of the methyl ester with yel HgO, under cooling. This salt is probably expl (Compare with Hg salt of ethyl ester)... 

Its Potassium salt, deliquescent crysts Mercury salt, pltlts, dec >240°and Silver salt, voluminous ppt, explodes violently when heated have been prepd in addn to many other derivs (Ref 1) l,l-Dimethyl-2-propyn-l-nitrite 3,3-Dimethyl-l-propyn-3-ol (called Nitrite Ester of 2-Methyl-3-hutyn-2-ol in CA), HCiC.C(CH3)2.ONO mw 113.11, N 12.38% liq, hp 80-82° at 750mm press nD 1.3926 at 20° was prepd when NOCl ether were added to a stirred soln of 3 methyl-l-butyn-3-oI (parent compd)... 

Bouveault1 claims that the yield of adipic acid is better on electrolyzing the methyl ester-salt in methyl-alcoholic solution. He obtained a yield of 80% by using a mercury cathode and a hollow platinum spiral anode, through which a current of cold water was passed. The acid succinic methyl ester occurs as the principal by-product, also a neutral methyl ester of a tribasic acid which was not investigated. 

Experimental details solid-state photolysis 957 A crushed crystalline ketone (279a or 279b) ( 5 mg), suspended in hexane (3 ml), was placed between Pyrex microscope slides, sealed in a polyethylene bag under nitrogen and irradiated with a medium-pressure mercury lamp (450 W) at a distance of 10 cm from a water-cooled Pyrex immersion well (Figure 3.9) at either 20 or — 20 °C (cryostat ethanol bath). The product, a chiral organic salt, was derivatized to the corresponding methyl ester by treatment with excess diazomethane and purified by column chromatography. 

A more recent synthesis of 3-methylenecephams from cephalosporins utilizes mercury salts in a metal-assisted reaction with 3-methyl-3-hal-ocepham ester sulfoxides. Although ordinarily dehydrohalogenations of 3-halo-3-methylcephams lead to the thermodynamically more stable 3-methyl-2-cephems and -3-cephems, chemists at Dista Products Limited (England) discovered that electrophilic mercury salts specifically led to 3-methylenecephams (Corfield and Taylor, 1978). When p-nitrobenzyl 7-phenoxyacetamido-3-methyl-3-bromo(or 3-iodo)cepham-4-carboxylate 1-oxide (47) was treated with mercury(I or II) perchlorate in dimethox-yethane for 18 hr at room temperature, p-nitrobenzyl 7-phenoxyacetam-ido-3-methylenecepham-4-carboxylate 1-oxide (48) was obtained in 75% yield. No other metal salt (in a variety of solvents) effected this transformation. Their view of the mechanism of this reaction is detailed later in this chapter. 

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