The Hydroxylation of the Double Bond¹

Abstract

Vol. 58and concentrated. There resulted a viscous yellow oil boiling at 280-285°( 2 mm.). The yield was 4.4 g. or 84.1%. Anal. Caled, for CuHieOaBr: C, .5; , 4.1; -OCHs, 9.8. Found; C, 60.8; , 4.0; -OCHs, 10.0.o-Bromophenylglyoxylic Acid.-This acid was purified by several crystallizations from methyl alcohol and water. The thin colorless needles melted over a range with decomposition as reported by Russanow. For a concentra-tion of 0.03449, molecular conductivity 266.21, and conductivity at infinite dilution 348, the ionization constant at 25°was calculated to be 8.6 X 1Q-Z.

A symmetry-driven approach to the putative spiroketal core of the didemnaketals

“…There are two practical alternatives to using potassium ferricyanide: Milas conditions employ hydrogen peroxide 37 while Upjohn conditions make use of N-methylmorpholine N-oxide. 38 Both oxidants offer the advantage that they are active at neutral pH, which we hoped would help to impede the unwanted conjugate addition.…”

Manganese‐Catalyzed Oxidation with Hydrogen Peroxide

“…The templating approach allows for two ligands to be immobilized in proximity to each other and thereby overcomes this problem. [112], or other oxidants [113] is the method of choice for this transformation [114]. The introduction of the highly enantioselective OsO 4 -catalyzed dihydroxylation by Sharpless and its extensive use in synthetic chemistry in recent years have provided ample demonstration of the key role of this oxidation reaction [115].…”

Lanostane to cucurbitane transformations

“…3P-Acetoxy-9a-hydroxy-5a-lanosta-7,ll -dione (7) (a) By osmium tetroxide -hydrogen peroxide oxidation of 5 (7,9). Two grams of osmium tetroxide was added to a solution of 3.8 g of 9,ll-olefin 5 in 25 mL of dry pyridine.…”