Sung Kwon Kang

Selective N-Demethylation of Tertiary Aminofumagillols with Selenium Dioxide via a Non-classical Polonovski Type Reaction

The previously unknown selective N-demethylation of tertiary aminofumagillols (5a-e) to the corresponding secondary aminofumagillols (7a-e) is effectively accomplished via a non-classical Polonovski type reaction using selenium dioxide (SeO 2 ). Especially, noteworthy is that two epoxy and the α,β-unsaturated ester functionalities in the fumagillol molecules tolerate in this transformation. Aminofumagillol derivatives are valuable antiangiogenesis inhibitors.

Selective reduction of nitrocinnamoylfumagillols with α,β-unsaturated ester using borohydride exchange resin (BER) - nickel acetate

Borohydride Exchange Resin (BER) - nickel acetate system readily reduces nitrocinnamoylfumagillols to the corresponding amines in excellent yields, high chemoselectivity, and simple procedure. Especially, this system tolerates two epoxides (spiro-epoxide and the one on C4 alkene side chain) and the α,β-unsaturated ester moiety at C6 on the fumagillol.

EFFECTIVE PROCEDURE FOR THE OXIDATIVE CLEAVAGE OF OLEFINS BY OsO4-NaIO4

Oxidative cleavage of olefins by OsO 4 -NaIO 4 sometimes suffers from low yields due to the formation of side products. It is reported that the addition of pyrimidine can suppress the side reactions and dramatically improve the yield of this classic reaction.