✍ Scribed by S.William Pelletier; Atanas P. Venkov; Janet Finer-Moore; Naresh V. Mody
No coin nor oath required. For personal study only.
yield in the presence of aZwrrina. In the absence of atwrina, the reaction does not proceed or takes place in low yieZd with many side products after q long reaction time.
Recently organic reactions on alumina surfaces have generated a great deal of interest among synthetic organic chemists because of their exceptionally high selectivity under mild reaction conditions.' Usually Michael addition of a secondary amine to o,f+unsaturated carbonyl-containing compounds proceeds in goad yield without any catalyst, but we observed that in the case of exocyclic c,P-unsaturated ketones, the addition does not occur 0' takes place in low yield after a long reaction time. 1 2 We naw report an alumina-catalyzed Michael addition of secondary amines to exocyclic a,P-unsaturated ketones. During an investigation of C2e -diterpenoid alkaloids, we observed the addition of diethylamine in the presence of neutral alumina of activity III to the a,P-unsaturated ketone, veatchinone (11, to afford compound 2, C2&142~4, mp. 116-l 170, in quantitative yield. This reaction did not proceed in the absence of alumina or in the presence of alumina of activity I. The structure of compound 2 was established by a single-crystal X-ray analysis (Figure 1) and other spectroscopic methods. Crystals of compound 2 were
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