Organomagnesiums lead oxides

The much simpler steroid, 253, was fortuitously found to fulfill this role when injected into animals. Its lack of oral activity was overcome by incorporation of the 7a-thioacetate group. Reaction of the ethisterone intermediate, 77b, with a large excess of an organomagnesium halide leads to the corresponding acetylide salt carbonation with CO2 affords the carboxyllic acid, 251. This is then hydrogenated and the hydroxy acid cy-clized to the spirolactone. Oppenauer oxidation followed by treatment with chloranil affords the 4,6-dehydro-3-ketone (254). Conjugate addition of thiolacetic acid completes the synthesis of spironolactone (255), an orally active aldosterone antagonist. ... 

Addition of oiganditfaiuin and organomagnesium reagents to such vinyl(alkoxy)silanes, followed by catalyzed coupling of the new organometallic with either vinyl or allyl bromide, leads,after oxidative cleavage, to allylic or homoallylic alcohols, respectively (Scheme 9). 

Electrolysis of organomagnesium chlorides in ethereal solution using a sacrificial black phosphorus anode, is reported to yield tertiary phosphines A tertiary phosphine oxide, tris (hydroxymethyl) phosphine oxide is produced in 64% yield (60% with respect to current) in the electrolysis of white phosphorus in a solution containing acetic acid, HCl, (CH3CO2)2Zn, (to improve the conductivity) and formalin and using a lead cathode. Tris (ct-hydroxyethyl) phosphine oxide was similarly obtained in 42% yield ... 

The reaction of the rhodium(l) complex (CXLV) and organolithium or organomagnesium compounds produces the alkylrhodiums (CXLVI). Oxidative addition of an acid chloride to this intermediate, followed by reductive elimination, leads to unsymmetrical ketones in good yields. The alkyirhodium (CXLVI) does not react with aldehydes, esters, or nitriles. An additional benefit is that the starting rhodium complex (CXLV) is regenerated in reusable form in the last step (Hegedus et al., 1973, 1975a). Reaction of... 

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