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Camptothecin (CPT) is an important natural product targeting to Topoisomerase I (Topo I). Despite the high antitumor activity, this compound cannot enter clinical trial owing to its high toxicity and low bio‐availability. In this project, the ring‐closing metathesis (RCM) synthesis strategy was employed to introduce spirocycle functional group in the 5‐position of CPT. Thus, in the catalysis of Grubbs II catalyst, 5,5‐diallylcamptothecin underwent RCM reaction to give 5‐spirocycle CPT compound in 73% yield. [ABSTRACT FROM AUTHOR]

As a main bioactive component extracted from Evodiae fructus, evodiamine has a variety of pharmacological activities. In this paper, evodiamine was chosen as starting material to react with different halides. Upon treatment of TFA, a series of novel ring‐opening evodiamine derivatives 3a–o were successfully synthesized in a moderate to high yields. These obtained compounds exhibit a moderate to good antitumor activity against BGC803 and SW480 in vitro test by MTT assay. The results showed that hexyl substituted evodiamine derivative (3j, R=hexyl) has a strong antitumor activity against BGC803 and SW480. [ABSTRACT FROM AUTHOR]

A new convenient base promoted aromatization process has been developed to prepare substituted 3‐hydroxybenzene dicarboxylate using commercially available materials. In particular, regioselectivity will occur for substrates with mono‐substitution at 5‐ or 6‐position. This new process provides less reaction steps and moderate yields, and can be used extensively in the synthesis of other substrates to functionalize phenol esters. [ABSTRACT FROM AUTHOR]

In competition with Michael addition between oxabornene and amines, a cascade substitution reaction predominates to generate cyclohexa‐1,4‐diene‐3,6‐diamine and amino alcohol in a moderate yield. This method has wide universality for different amines, overcomes the shortcomings of Michael addition reaction that cannot be synthesized due to shortage of raw materials, and can be further applied to the total synthesis of some related natural products. [ABSTRACT FROM AUTHOR]

A convenient method was developed to prepare the diastereomer of dolutegravir tricyclic intermediate in the catalysis of EDCI/DMAP in up to 87% yield. Different solvents, temperature, and times were optimized. The synthesized diastereomer 6′ could be used as a standard for the industrial manufacture requirement of dolutegravir active pharmaceutical ingredient. [ABSTRACT FROM AUTHOR]

A new series of norcantharidin salt derivatives was designed and synthesized in good yield. The compounds structures were characterized by 1H‐NMR, 13C‐NMR, and IR spectra. These norcantharidin salts 5 exhibit good antitumor activity against both liver cancer and colon cancer cell lines in vitro, which seems to direct a right trend for the modification on cantharidin structure. [ABSTRACT FROM AUTHOR]

4‐Methylimidazole‐2‐carboxylic acid was synthesized from 4‐methylimidazole with a total yield of 65% over four steps including an N‐benzyl protection, acylation, debenzylation, and ester hydrolysis. The solvent, base, temperature, and reaction time are optimized for this method. This efficient, convenient, and low‐cost protocol uses inexpensive reagents in each step to obtain 4‐methylimidazole‐2‐carboxylic acid in high yield. [ABSTRACT FROM AUTHOR]