Categories: Synthesis of O-Heterocycles
Synthesis of 2,3- and 4,5-Dihydrofurans
Recent Literature
A planar-chiral bipyridine ligand enables diastereo- and enantioselective
copper-catalyzed [4+1] cycloadditions of enones with diazo compounds to produce
highly substituted 2,3-dihydrofurans. The method is applied to a catalytic
asymmetric synthesis of a deoxy-C-nucleoside.
S. Son, G. C. Fu, J. Am. Chem. Soc., 2007,
129, 1046-1047.
A highly chemo-, regioselective, and efficient Pd(0)-catalyzed
coupling-cyclization of 2-(2',3'-allenyl)acetylacetates with organic halides
using K3PO4 as base in DMF afforded 4,5-dihydrofuran
derivatives in good yields.
S. Ma, Z. Zheng, X. Jiang, Org. Lett., 2007,
9, 529-531.
A new method for the synthesis of 2,3-dihydrofurans from readily available
starting enones and pyridinium salts has been developed. This protocol can
provide a novel and effective methodology for the preparation of
2,3-dihydrofurans in a stereoselective fashion. A one-pot process was also
developed, in which the pyridinium salts were generated in situ from
corresponding halides.
S. Xue, L. He, Y.-K. Liu, K.-Z. Han, Q.-X. Guo, Synthesis, 2006, 666-674.
An olefin metathesis/double bond migration sequence of allyl ethers to cyclic
enol ethers is catalyzed by first and second generation Grubbs' catalysts. These
ruthenium carbene complexes were activated to catalyze the double bond migration
by additioin of hydride sources, such as NaH or NaBH4.
B. Schmidt, Eur. J. Org. Chem., 2003, 816-819.
