Glycosylation of cardenolides. VIII. Structures of the by-products of the synthesis by the orthoester method of strophanthidol rhamnosides
The by-products formed in the preparation of strophanthiodol 19-rhamnoside and 3, 19-bisrhamnoside by the orthoester method are 3β,5-dihydroxy-8,19-epoxy-5β,14β, 17α-card-20(22)-enolide and its 3-α-L-rhamnoside. 3β,5-Dihydroxy-8,19-epoxy-5β, 14α,17β-card-20(22)-enolide has been obtained by the action of a solution of HBr in nitromethane on strophanthidol.
Untersuchungen über Steroide XLII. Umwandlung des 17α‐Pseudostrophanthidins in 19‐Hydroxy‐8, 19‐epoxy‐14β, 17α‐cortexon und 8‐Hydroxy‐19‐nor‐14β, 17α‐cortexon
The synthesis of a structural isomer of aldosterone, viz. 19-hydroxy-8, 19-epoxy-(11-) de(s)oxycorticosterone (= 19-hydroxy-8, 19-epoxy-cortexone), and a number of related compounds was reported earlier from this laboratory [1]. It appeared desirable to prepare the corresponding compounds of the 17α-series also, such as 19-hydroxy-8, 19-epoxy-14 β, 17 (βH)-deoxycorticosterone (28). 17 α-Pseudostrophanthidin (2), which has not yet been described in the literature, was considered as starting material for the synthesis of 28. 2 has now been prepared by heating a solution of pseudostrophanthidin (1) in dimethylformamide in the presence of sodium p-toluenesulfonate and anhydrous sodium acetate. 2 was characterized as the 3, 19-diacetate (7), the 19-methylal (8) and the 3-monoacetat (9). 9 was also obtained by acetylating the methylal 8 and demethylating the resulting reaction product 10. To support the structures assigned to 9 and, by implication, to 2, a series of further reactions were carried out.
Optical rotatory dispersion studies, IL. Über Trithione, XV: Die anomale Rotationsdispersion optisch aktiver Terpen‐trithione
Das (+)-Campho-trithion (I) hat (in Isooctan) ein typisches Trithion-Absorptionsspektrum mit Maxima bei 225, 248, 281, 342 und 417 mμ sowie einer schwachen Schulter bei etwa 495 mμ. Trotz der hohen Extinktion von I gelang die Messung der vollstandigen Rotationsdispersionskurve zwischen 650 und 260 mμ; sie zeigt eine Serie von 4 positiven Cotton-Effekten, in der Lage entsprechen den 4 langwelligsten Maxima der Absorptionskurven, die somit alle aktiv sind. Analog verhalt sich das aus (+)-α-Pinen gewonnene Trithion (II) mit 4 negativen Cotton-Effekten.