Two optically active N-acetyldopamine dimers together with four phenolic monomers were isolated from the crude drug "Zentai," a cast-off shell of the cicada of Cryptotympana sp. (Cicadidae). The former two were 2-(3',4'-dihydroxyphenyl)-1,4-benzodioxane derivatives carrying substituents at the 3 and 6 (or 7) positions, which are known to be components of sclerotized insect cuticles. Their structures including absolute configurations were determined on the basis of NMR and circular dichroism (CD) spectroscopic data.

2,3,4,6-Tetra-O-benzyl-d-mannopyranose was prepared from methyl α-d-mannopyranoside. Improved preparations of 2,3,4,6-tetra-O-benzyl-α-d-glucopyranose and -galactopyranose are described.

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Die Titelverbindung (IV) wird durch Benzylierungvon Methyl‐oz‐D‐mannopyranosid (I) mit einem Überschuß an Benzylchlorid (II) in Gegenwart von NaH und anschließende Hydrolyse des Pyranosid‐Derivats (III) synthetisiert und als p‐Nitrobenzoat charakterisiert.