Die Konfiguration Der α‐ Und β‐Eläostearinsäure

Abstract

Die Elaostearimiiuren und die Licanstiuren zeigen bei der Dien-Synthese, soweit bis jetzt zu ersehen ist, ein analoges Verhalten. Da die Entwicklung bei der Ellostearinsaure weiter vorangeschritten ist als im Falle der Licansaure, beschranken wir unsere Darstellung auf die zuerst genannte. Nach den Untersuchungen von J. BOESEKEN~), H. P. KAUFMANN~) und R. S. MORRELL~) und ihren Mitarbeitern besitzt die Elaostearinsaure die Konstitution I einer Octadeca-trien-(9.11 .I 3)-saure-( 1). CH~-(CHZ)~-CH=CH-CH=CH-CH= CH-(CH2),-COzH

Stereochemistry of the Diels-Alder Reaction.

“…By this method dimorphecolic acid (XIV) was shown to be a trans,trans diene (266), the dehydration product (XV) of ricinelaidic acid ("Mangold's acid") was also shown to be a trans,trans diene (24), and the configuration of the diene substituent in the pyrethrolones (XVI) was shown to be trans (132). Configurations have also been assigned to the triene systems in «-and /3-eleostearic acids (XVII) (24,100) and their isomer punicic acid (144), «-and /3-licanic acids (XVIII) (216), the isomers of the tetraene, parinaric acid (XIX) (184), alioand neoalloocimene (XX) (13,117), and a series of simple trienes (7) by the use of the Diels-Alder reaction. This method was also of great utility in elucidating the structure and stereochemistry of irradiation products of ergosterol (149).…”

1,4-Disubstituted Anthracene Antitumor Agents

“…This solution was washed with 5% sodium bicarbonate solution (2 × 200 mL) and water (2 × 200 mL), dried (Na 2 SO 4 ), and concentrated on a rotary evaporator. This procedure gave 16.5 g (57.5%) of 8 as a pale yellow solid: mp 138−140 °C (lit . mp 141−142 °C); 1 H NMR 2.59 (s, 6), 7.40 (br s, 2), 7.73 (br s, 2), 8.13 (br s, 2); IR 3000−3600, 1650, 1310, 1240 cm -1 ; MS 236 (M + ).…”

“…The first step in the preparation of 13 was formation of 1,4-dimethylanthraquinone ( 8 ) (Scheme 1). This compound had been prepared previously by a Diels−Alder condensation of 1,4-naphthoquinone with 2,4-hexadiene followed by air oxidation in alkaline solution . We found it more convenient to prepare 8 by Friedel−Crafts acylation of 1,4-xylene with phthalic anhydride followed by cyclization of the crude intermediate in sulfuric acid.…”