Durch eine Grinardierungs — Oxidations‐Sequenz, ohne Isolierung von Zwischenprodukten, läßt sich δ‐Valerolacton (4) sehr einfach in δ,δ‐disubstituierte δ‐Lactone 6 überführen. Genauer untersucht wurde der Reaktionsverlauf am Beispiel der Synthese von δ,δ‐Diphenyl‐δ‐valerolacton (6a) aus 4.

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Treatment with tris-(dimethylamino)-methane resp. formylation and reaction with piperidine transfer 1 to 5a,b, which can not be reduced to the corresponding alpha-aminomethyllactones 4a,b, in contrast to the homologue 6 and other alpha-aminomethylene-gamma- and delta-lactones. Isolation of products and gc/ms-investigations verify the reaction course: The aminomethyl moiety in alpha-position of delta,delta-diarylated delta-lactones is instable and eliminates amine to give 7 (NaCNBH3) or 9 (H2/Pt). Only cleavage of the lactone ring enables the formation of stable aminomethyl compounds (10,11). 5a shows weak parasympatholytic and no H1-antihistaminic activity at the isolated guinea-pig ileum.

γ‐Butyrolactone (I) is converted to the 5,5'‐disubstituted derivatives (III) by Grignard reaction and subsequent phase‐transfer catalyzed oxidation.

170ChemInform Abstract Consecutive reaction of the δ-lactone (I) with ethyl formate (IV)/sodium hydride and piperidine (V) leads to the formation of the 3-piperidinomethylenetetrahydro-2(2H)-pyranone (IIIb). Condensation of (I) and the γ-butyrolactone (VI) with tris(dimethylamino)methane (II) produces the 3-(dimethylaminomethylene)tetrahydropyranone (IIIa) and the 3-(dimethylaminomethylene)furanone (VII). Reduction of the compounds (III) and (VII) with NaCNBH3 gives the 3-methylenetetrahydropyranone (VIII) and the furanone (IX) respectively. Hydrogenation of (III) in the presence of PtO2 leads to the formation of the tetrahydropyranone (X), whereas the compounds (XI) and (XII) are obtained by hydrogenation of (IIIa) in the presence of Pd/C. The compound (IIIa) shows a weak parasympatholytic but no antihistaminic activity.