ChemInform Abstract: SYNTHESIS OF 7‐HYDROXYCADALENAL

Abstract

Die Titelverbindung (VI) wird durch sukzessives Dehydrieren des Ketoaldehyds (V) ‐ zuerst des funktionell substituierten Ringes mit DDQ, dann des zweiten Ringes katalytisch an Pd ‐ dargestellt.

Process‐Scale Total Synthesis of Nature‐Identical (−)‐(S,S)‐7‐Hydroxycalamenal in High Enantiomeric Purity through Catalytic Enantioselective Hydrogenation

“…The latter was obtained in 99.5% ee by kinetic resolution of the racemate (not commercially available, but easy to prepare), by means of an enzyme-catalyzed asymmetric esterification, followed by alkaline hydrolysis and column chromatography of the enantiomerically pure (R)-acetate (Scheme 3). Given the high number of steps, the use of critical reagents such as O 3 and LiAlH 4 (twice), and the extensive use of chromatographic purification procedures, this approach appears more an academic exercise than a method of true preparative value for the synthesis of (À)-2.…”

“…The structure of natural hydroxycalamenal ((À)-1a), with its relative cis-configuration [3] and absolute configuration [4], was elucidated through chemical correlation and spectroscopic analysis. As for the syntheses of (À)-1a, there are a large number of publications claiming successful achievement in terms of efficiency, chemical yield, and optical purity, but the accurate examination of the experimental details of these reports raises several doubts on the reliability and applicability of many of them.…”