The convergent synthesis of the Lewis A (Le(a)) tandem repeat is described. The Le(a) tandem repeat is a carbohydrate ligand for a mannose binding protein that shows potent inhibitory activity against carcinoma growth. The Le(a) unit, {β-d-Gal-(1→3)-[α-l-Fuc-(1→4)]-β-d-GlcNAc}, was synthesized by stereoselective nitrile-assisted β-galactosylation with the phenyl 3-O-allyl-2,4,6-tri-O-benzyl-1-t...

An enantioselective synthesis of the quinolizidine alkaloid (K)-lasubine II 1 is reported. Two different pathways to the key intermediate 2 are described. The first case involving a sequence of ring rearrangement metathesis (RRM), simple functional group interconversion operations, followed by a stereoselective cross metathesis (CM) and in the second case a domino ring opening-/ring closing-/ c...

Levoglucosenone (1), a readily availabie carbohydrate from the pyrolysis of cellulose, has been attracting attention as a chiral starting material with multifunctional groups.i) Its unique structure, being highly oxygenated but with no hydroxy greups, provides a great advantage for multi-step synthesis. Levog[ucosenone (1) requires none of the protect]'ere-deprotection steps of hydroxy groups t...

An enantioselective approach to (-)-isoavenaciolide was achieved starting from 1-undecyn-3-ol. The synthesis relied upon the preparation of a chiral 4-silyloxy-2-alkenylborane by hydroboration of a protected 2,3-allenol and subsequent stereoselective addition to 2-thiophenecarboxaldehyde.

The first total synthesis of (-)-16-episilicine has been completed from a phenylglycinol-derived bicyclic lactam, the key steps being stereoselective conjugate addition and alkylation reactions, and a ring-closing metathesis.

Palladium-catalyzed cyclization of β-alkylthio dienone derivatives affords 2-cyclopentenones in a regio- and stereoselective manner in the presence of silane. C-S activation, intramolecular carbopalladation and hydrogenolysis construct the cascade process.

Stereoselective construction of the highly oxygenated decahydrocyclopenta[g]chromene skeleton, which is the tricyclic core of leucosceptrine, which possesses prolylendopeptidase inhibitory activity, and leucosesterterpenone, which exhibits anti-angiogenic activity, from Leucosceptrum canum, was achieved.

A stereoselective gold-catalyzed [2 + 2 + 2] cycloaddition of ketoenynes substituted at the propargylic position with OR groups has been applied for the synthesis of (+)-orientalol F and pubinernoid B.

A novel, efficient and atom-economic Rh-catalyzed stereoselective tandem nucleophilic addition/bicyclization for the synthesis of 2,3-fused bicyclic furans from readily available acyclic diyne-enones and alcohols has been developed.