Reactions of beta-Ferrocenylethyl- and gama-Ferrocenylpropyl Bromide with Hydroxyaliphatic Acid Esters
In our previous investigations reactions of ferrocyl acetates and derived quaternary salts with alkoxides formed from methyl 2-hydroxyalkanoates were performed, giving methyl ferrocyloxyalkanoates and ferrocyl methyl ethers.1 This report is dealing with transformations of the same alkanoates with the homologous substrates containing ferrocene nucleus in b- and g-position in relation to (against, towards) the reaction center. By action of PBr3 on FcCH2CHROH (1a, R=H; 1b, R=Me; 1c, R=Ph) and FcCH2CH2CH2OH (2) in benzene abs. the corresponding bromides FcCH2CHRBr (3a, R=H; 3b, R=Me; 3c, R=Ph) and FcCH2CH2CH2Br (4) were obtained. Heating of compounds 3 and 4 in a large excess of methyl glycolate or methyl lactate in the presence of sodium gave 31-65% of transesterification products accompanied by a small quantity of w-ferrocenyloxaalkanoates 7. Mechanisms expliciting the different course of reactions performed and those described in paper1 will be presented.