Total synthesis of antifungal gamahonolide A

The first stereoselective total synthesis of gamahonolide A (1) has been accomplished using aminoxylation, Keck allylation, and ring-closing metathesis (RCM) reactions as key steps.     

One Pot Synthesis of 4-(2-Hydroxybenzoyl)-pyrazoles from 3-Formylchromones Under Microwave Irradiation in Solvent Free Conditions

The synthesis of 4-(-2-hydroxybenzoyl)pyrazoles (3) was achieved in a single step by the reaction of 3-formylchromones (1) with Phenylhydrazine or Tosylhydrazine under microwave irradiation without a solvent.     

Stereoconvergent synthesis of C1-C17 and C18-C25 fragments of bafilomycin A1

The effective syntheses of the enantiomerically pure C1-C17 2 and C18-C25 3 fragments as promising synthetic intermediates of bafilomycin A₁, 1 have been achieved.     

Formal Synthesis of Natural 1,3‐Polyol/α‐Pyrone Diastereoisomers

A stereoselective formal synthesis of diastereoisomers of 1,3‐polyol/α‐pyrone antifungal natural products isolated from Ravensara anisata has been achieved involving epoxide opening and asymmetric allylation as key steps.     

Synthesis, characterization and photophysics of alkyne bridged bimetallic rhenium(I) and ruthenium(II) complexes

Six new homobimetallic and heterobimetallic complexes of rhenium(I) and ruthenium(II) bridged by ethynylene spacer [(CO)₃(bpy)Re(BL)Re(bpy)(CO)₃]²⁺ [Cl(bpy)₂Ru(BL)Ru(bpy)₂Cl]²⁺ and [(CO)₃(bpy)Re(BL)Ru(bpy)₂Cl]²⁺ (bpy = 2,2′-bipyridine, BL = 1,2-bis(4-pyridyl)acetylene (bpa) and 1,4-bis(4-pyridyl)butadiyne (bpb) are synthesized and characterized. The electrochemical and photophysical properties of all the complexes show a weak interaction between two metal centers in heterobimetallic complexes. The excited state lifetime of the complexes is increased upon introduction of ethynylene spacer and the transient spectra show that this is due to delocalization of electron in the bridging ligand. Also, intramolecular energy transfer from *Re(I) to Ru(II) in Re–Ru heterobimetallic complexes occurs with a rate constant 4 × 10⁷ s⁻¹.     

Ceria/vinylpyridine polymer nanocomposite: an ecofriendly catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones

The three-component condensation of aldehydes, β-ketoesters and urea has been carried out in water using ceria (cerium oxide, CeO₂) nanoparticles supported on poly(4vp-co-dvb) as a catalyst for the preparation of 3,4-dihydropyrimidin-2(1H)-ones in good yields. The catalyst was recovered easily and reused without loss of its activity.     

A Sakurai-Prins-Ritter reaction sequence for the diastereoselective synthesis of 4-amidotetrahydropyrans catalyzed by bismuth triflate

The synthesis of 4-amidotetrahydropyrans has been achieved by a single-step Sakurai-Prins-Ritter reaction sequence in a domino fashion by the reaction of an aldehyde and allyltrimethylsilane in acetonitrile using Bi(OTf)₃ as catalyst. The present synthesis is highly efficient and diastereoselective.     

Stereoselective total synthesis of polyketide lactone, (3R,4S,5S,9S)-3,5,9-trihydroxy-4-methylundecanoic acid δ-lactone

The total synthesis of lactone 1 has been described. The convergent asymmetric synthesis relies on the use of an Evans’ syn-aldol, chain extension with lithio tert-butyl acetate, and the stereoselective reduction of a ketone as the key reactions.     

Total synthesis of the Z-isomers of nonenolide and desmethyl nonenolide

RCM and Yamaguchi esterification reactions were used as the key steps for the stereoselective total synthesis of Z-isomers of nonenolide and desmethyl nonenolide.     

Tandem α-aminoxylation-allylation reaction based approach for the synthesis of goniothalesdiol A, leiocarpin A and (+)-goniodiol

A short and efficient syntheses of goniothalesdiol A, leiocarpin A, and (+)-goniodiol are reported by a convergent strategy using tandem aminoxylation-allylation reaction as a key step starting from benzaldehyde.