engleski

Reactions of Ferroceylalkanols with Ethyl Mercaptoalkanoates

The reactions of ferrocene reagents Fc(CH2)nCHRX (n=0-2 ; R=H, Me, Ph ; X=OH, Br) with diethyl malonate were described in our previouswork.1 Thereby transformations with alpha-substituted derivatives (n=0) gave malonic ester synthesis products, whereas beta- and gama-ferrocenylalkanols were transformed into transesterification products. In this report of the similar reagents 1 with mercaptoaliphatic acids and esters are described. These transformations were done under the identical conditions to those described in the mentioned paper. Ethyl thioglycolate and ferrocenylmethanol (1, n=1) gave substitution products 2, and higher carbinols 1 (n=2, 3) were converted into transesterification products 3. Reactions of bromides 1 (n=2, 3) with mercaptoaliphatic acids in MeOH/ NaOH gave compounds 4. The same acids were obtained by acid catalyzed SN-conversions of ferrocene carbinols with thioglycolic acid. The general mechanism of the reactions described will be presented. Results obtained corroborated again the well-known stability of ferrocyl cation, and indicaed stabilization effect of ferrocene nucleus on beta-ferrocenyl carbocations.

ferrocenylalkanols; ethyl mercaptoalkanoates; malonic ester synthesis products; transesterification products beta-ferrocenyl carbocations

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