ol6b00064_si_002.cif (60.35 kB)
Oxidative Cyclization of 1,5-Dienes with Hydrogen Peroxide Catalyzed by an Osmium(III) Complex: Synthesis of cis-Tetrahydrofurans
dataset
posted on 2016-03-07, 19:21 authored by Hideki Sugimoto, Takayuki Kanetake, Kazuki Maeda, Shinobu ItohStereoselective oxidative cyclization
of 1,5-dienes with hydrogen
peroxide catalyzed by [OsIII(OH)(H2O)(L–N4Me2)](PF6)2 (1: L–N4Me2 = N,N′-dimethyl-2,11-diaza-[3,3](2,6)pyridinophane)
is explored. 1,5-Dienes involving geraniol derivatives are converted
to the corresponding tetrahydrofurans in modest to high yields. The
products exclusively have the cis-conformation with
respect to the substituents at the 2- and 5-positions of the tetrahydrofuran
ring. The products also have a syn-conformation with
respect to the furan oxygen atom and the hydroxyl groups. Mechanistic
studies including a direct reaction of the oxo-hydroxo-osmium(V) complex, 2, with a dihydroxylated geraniol derivative are performed.