An ellagic acid-related natural product, nigricanin (1), was synthesized via the Ullmann coupling reaction of 2-bromo-3,4-dialkoxybenzaldehyde (4) followed by the Cannizzaro reaction for desymmetrization of the symmetric biaryl compound (5). Compared to our previously reported study, the presented synthesis improved the sequence step number.

Decahomotetrathiacalix[6]arenes were conveniently prepared from the 2:2 cyclization reactions of bis(chloromethyl)phenol‐formaldehyde trimers with 1,2‐ethanedithiol in high yields. In contrast, the simi lar reactions of the trimers with 1,3‐propanedithiol instead of 1,2‐ethanedithiol gave 1:1 macrocycles, hexahomodithiacalix[3]arenes, in good yields. Homoazacalixarenes were also prepared from the analogous reactions using piperazines. These macrocycles adopt a cone‐like form as a preferable conformation in solution.

Die in situ aus (I) generierten mesoionischen Verbindungen (II) bilden mit (III) bzw. (VII) die Cycloaddukte (IV) und (V) bzw. (VIII) und (IX), von denen (IV) zu den Estern (VI) umge‐ setzt wird.

Das Pyridiniumbetain (I) bildet mit den substituierten Ethylenen (II) die normalen Cycloaddukte (III) und (IVa) sowie die unerwarteten Cycloaddukte (Va), (Vc) und (VIc).

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