Zur Synthese von Homocamphenilansäure

Syntheses of the title compound and of some of its derivatives are described. Homocamphenilanic acid could not be obtained by aDiels-Alder reaction of cyclohexadiene with an appropriate dienophile but is easily accessible via homocamphene by hydroboration of this homoterpene and subsequent oxidation of the reaction product.

Anmerkung: Zur Verwendung der Vorsilbe Homo- im Zusammenhang mit Norbornanen siehe Lit. [13] und Fußnote in Lit. [12].     

Wisanin und andere amide der 5-(2-methoxy-4,5-methylendioxyphenyl)-2,4-pentadiensäure: Synthesen,spektroskopische untersuchungen und prüfung auf antibakterielle wirksamkeit

Wisanine, a constituent of piper guineense (a plant of which antibacterial activity has been reported and other amides of 5 - (2 - methoxy - 4, 5 - methylenedioxyphenyl) - pentadienoic acid were synthesized from 3,4 -dioxymethylen - phenel and investigated spectroscopically. The amides prepared have been tested against grampositive and gramnegative bacteria. Only some of the amides prepared show weak antibacterial activity.     

Efficient conversion of O-substituted 3-hydroxy-4-imino-oxazolidin-2-ones into O-substituted alpha-hydroxyamidoximes

An efficient and convenient two-step synthesis of O-substituted alpha-hydroxyamidoximes has been developed. The first step involves a high-yielding one-pot synthesis of the so far unknown O-substituted 3-hydroxy-4-imino-oxazolidin-2-ones by reacting cyanohydrins stepwise with 1,1'-carbonyldiimidazole and O-substituted hydroxylamines. The second step represents a novel, sodium methoxide-mediated conversion of O-substituted 3-hydroxy-4-imino-oxazolidin-2-ones into the corresponding O-substituted alpha-hydroxyamidoximes. [reaction: see text]     

Synthesis and Diels-Alder Reactions of a New Kind of Chiral Dienophiles: Cyclic Vinyl-p-tolylsulfilimines

A new kind of chiral dienophiles, cyclic vinyl-p-tolylsulfilimines (2a and 2b), were obtained from the corresponding (Z)-sulfinylacrylonitriles with HBF(4) and methanol. The asymmetric Diels-Alder reaction of optically pure 2a with cyclopentadiene under mild thermal or catalyzed conditions afforded only the endo-4a adduct with complete endo and pi-facial selectivities. The ability of the sulfilimine moiety to enhance the dienophilic reactivity of the double bond is similar to that of the sulfinyl group.