Studies on Oxidopyrylium [5 + 2] Cycloadditions: Toward a General Synthetic Route to the C12-Hydroxy Daphnetoxins
摘要:
[GRAPHICS]12-Hydroxydaphnetoxins, members of the structurally fascinating daphnane diterpene family, exhibit a wide range of significant biological activities. A general route to the BC-ring system of 12-hydroxy daphnetoxins is reported based on D-ribose. Depending on the choice of protecting groups and solvent, the oxidopyrylium-alkene [5+2] cycloaddition originating from A provides cycloadduct diastereomer B or C with good to excellent selectivity.
Studies on Oxidopyrylium [5 + 2] Cycloadditions: Toward a General Synthetic Route to the C12-Hydroxy Daphnetoxins
摘要:
[GRAPHICS]12-Hydroxydaphnetoxins, members of the structurally fascinating daphnane diterpene family, exhibit a wide range of significant biological activities. A general route to the BC-ring system of 12-hydroxy daphnetoxins is reported based on D-ribose. Depending on the choice of protecting groups and solvent, the oxidopyrylium-alkene [5+2] cycloaddition originating from A provides cycloadduct diastereomer B or C with good to excellent selectivity.
Regioselective Conversion of Primary Alcohols into Iodides in Unprotected Methyl Furanosides and Pyranosides
作者:Robert Madsen、Philip R. Skaanderup、Carina Storm Poulsen、Lene Hyldtoft、Malene R. Jørgensen
DOI:10.1055/s-2002-33641
日期:——
the primary hydroxy group in methyl glycosides with iodide. The first method is a modification of a literature procedure employing triphenylphosphine and iodine, where purification has been carried out on a reverse phase column in order to efficiently separate the desired iodoglycosides from triphenylphosphine oxide. The second method employs a new procedure using sulfonylation in pyridine with sterically