Oestrone, formation

The aromatic ring of oestradiol or oestrone methyl ether readily forms a tricarbonyl chromium (0) complex in which the 13C signals from the aromatic ring are shifted strongly upheld (by ca. 14—34 p.p.m.). Smaller upheld shifts for other carbon atoms close to the aromatic ring (e.g. 2 p.p.m. for C-6) have been used to settle uncertainties in the earlier literature concerning the assignments of individual 18C resonances.69 13C N.m.r. spectra discriminate between A4- and A5-isomers of spiro-3-steroidal ketone derivatives thiazolidine formation results only in the (3i )-isomer (12), whereas hemithioacetals are mixtures of the (3R)- and (35)-forms.80... 

Treatment of oestrone with tetraphenylbismuth monotrifluoroacetate gave oestrone phenyl ether and exemplified, in part, a new procedure for aryl ether formation.31 A detailed study was reported of the formation of benzyl ethers by sequential reaction of alcohols with chloro(phenylmethylene)dimethylammonium chloride and sodium hydrogen telluride.32 Steroidal alcohols, inter alia, were converted into hydrolytically stable silyl ethers by reaction with B N Sil or BulPh2I which were generated in situ from the selenosilane and iodine.33 The 5a-hydroxycholestane (21) was protected in this way. 

Marks, F., and Hecker, E., Metabolism and mechanism of action of oestrogens XII. Structure and mechanism of formation of water-soluble and protein bound metabolites of oestrone in rat-liver microsomes in vitro and in vivo. Biochim. Biophy.s. Acta 187, 250-265 (1969). Masukawa, T., and Iwata, H., Possible regulation mechanism of microsomal glutathione S-transferase activity in rat liver. Biochem. Pharmacol. 35, 435-438 (1986). 

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