Piperazinomycin, a new antifungal antibiotic. II. Structure determination by X-ray crystallography

Exploiting ortho-substitution effect on formation of oxygen-containing [10]paracyclophane through ring-closing metathesis

The synthesis of strained paracyclophanes is facilitated byortho-substitution effect on phenyl ring.

Syntheses and biological activities of the proposed structure of apteniol A and its derivatives

We describe the syntheses of the proposed structure of diphenyl ether oxyneolignan, apteniol A and its derivatives. The diphenyl ether moiety of proposed apteniol A was formed via Ullmann ether synthesis, but the spectral data of the synthesized apteniol A did not agree with that in previous studies. The dimethyl ester derivative of the proposed apteniol A was found to enhance neurite outgrowth in PC12 cells and inhibit antigen-induced degranulation in RBL-2H3 cells.

A rapid access to biaryl ether containing macrocycles by pairwise use of Ugi 4CR and intramolecular S(N)Ar-based cycloetherification

[reaction: see text] From readily accessible starting materials, macrocycles with an endo aryl-aryl ether bond are synthesized in only two operations by combination of the Ugi four-component reaction and an intramolecular S(N)Ar reaction. The nitro group serves as an activator for the macrocyclization and provides a handle for the introduction of functional group diversity. A Ugi reaction promoted by ammonium chloride in aprotic solvent is documented for the first time.