engleski

Hydrolysis and retro-aldol clevage of 2-(1-adamantyl)-3-hydroxybutanoate: competing reactions

In the scope of our research on the synthesis of peptides and peptidomimetics with embedded cage molecules [1], we have prepared adamantane analogue of ethyl 3-hydroxybutanoate [2]: threo-(1a) and erythro-(1b)-isomers of ethyl 2-(1-adamantyl)-3-hydroxybutanoate. In order to obtain the corresponding acid derivatives (2a) or (2b) [3], ethyl esters threo-1a and erythro-1b were submitted to the base hydrolysis. Surprisingly, the main product was 1-adamantylacetic acid (3), indicating that retro-aldol reaction [4] is in competition with hydrolysis. On the other hand, the parent compound without adamantyl substituent, ethyl 3-hydroxybutanoate (4) was efficiently hydrolyzed without retro-aldol reaction. To get more insight in significant difference observed in the base induced reactions of adamantyl derivatives 1a, 1b and parent ester 4, these reactions were studied by computational methods. Herein, the comparison of theoretical and experimental results will be presented.

hydrolysis; retro-aldol reaction; threo- ethyl esters; erythro- ethyl esters

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