A short route to N-protected furanomycin, 5′-epi-furanomycin and isofuranomycin derivatives

Recent applications in natural product synthesis of dihydrofuran and -pyran formation by ring-closing alkene metathesis

Examples from 2003 to 2015 of ring-closing alkene metathesis (RCM) in the generation of dihydro-furans or -pyrans for natural product synthesis, are reviewed.

Stereoselective Pd-catalyzed etherification and asymmetric synthesis of furanomycin and its analogues from a chiral aziridine

A chiral aziridine was utilized for the synthesis of the anti-bacterial natural amino acid L-(+)-furanomycin, and its analogues including 5'-epi-furanomycin and norfuranomycin. Key steps of this synthesis are the stereoselective Pd-catalyzed etherification for diallyl ethers and ring closing metathesis.

Garner's aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

Since its introduction to the synthetic community in 1984, Garner's aldehyde has gained substantial attention as a chiral intermediate for the synthesis of numerous amino alcohol derivatives. This review presents some of the most successful carbon chain elongation reactions, namely carbonyl alkylations and olefinations. The literature is reviewed with particular attention on understanding how to avoid the deleterious epimerization of the existing stereocenter in Garner's aldehyde.

Cyclobutane amino acid analogues of furanomycin obtained by a formal [2 + 2] cycloaddition strategy promoted by methylaluminoxane

The synthesis and conformational analysis of a new type of conformationally restricted alpha-amino acid analogue of the amino acid antibiotic furanomycin is presented. The restriction involves the cis-fused cyclobutane and tetrahydrofuran units, generating the unusual 2-oxabicyclo[3.2.0]heptane core, which is found in a great number of biologically active natural products. The synthetic strategy is based on a formal [2 + 2] cycloaddition between 2-(acylamino)acrylates as acceptor alkenes and 2,3-dihydrofuran as a donor alkene, promoted by bulky aluminum-derived Lewis acids, particularly by methylaluminoxane (MAO). Additionally, following the same strategy, the synthesis of furanomycin analogues incorporating the 2-oxabicyclo[4.2.0]octane is reported.