Miroslav Havel

A Novel Indirect Preparation of Hemisuccinates

Abstract Hemisuccinates are prepared by condensation of succinic acid mono-2-(trimethylsilyl)ethyl ester with alcohols and subsequent aprotic removal of the protective group.

Synthetic approach to analogues of 19-norsteroids with an acyclic side chain

Racemic 14 beta-hydroxy-3-methoxy-8 alpha,9 alpha-1,3,5(10)-estratriene-17-one (I), obtained by total synthesis, was converted into a derivative with alkoxycarbonyl-ethylenic side chain, rac-(20E)-21-methoxycarbonyl-19-nor-8 alpha,9 alpha-pregna- 1,3,5(10),20-tetraene-3,14 beta-diol 3-methyl ether (XII) using two Wittig reactions. Analogous derivatives of 5 alpha-androstane were prepared as synthetic models. In the estrane series the stereochemistry of attachement of the side chain in position 17, biological activity of some compounds, and their chromatographic properties were investigated.

Reversed-phase high-performance liquid chromatographic separation of steroids with the β-crotonate side chain

An isocratic high-performance liquid chromatographic separation of some ethyl 3-stereoidyl crotonates [ethyl-24-nor-20(22)-cholen-23-oate derivatives] was developed. The separations were achieved by reversed-phase chromatography (Separon Si C18) using methanol, methanol-water, methanol-0.1 M formic acid and ethanol-0.01 M aqueous phosphoric acid mixtures as mobile phases. The steroidal crotonates were detected at 230 and 240 nm.