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Diels–Alder cycloaddition between an enantiomerically pure protected cis-cyclohexadiene diol metabolite and optically pure levoglucosenone derived from cellulose gave rise to complex pentacyclic natural product like structures in a chemically succinct process. The adducts were fully characterized and the observed results were in accord with theoretical calculations performed on the possible course of the reaction.

The first application of chiral auxiliaries synthesized from levoglucosenone (a biomass-derived anhydrosugar) in asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides is herein reported. The corresponding pyrrolidinic cores were obtained in excellent levels of regio and stereocontrol, good to excellent π-facial selectivities, and could be isolated enantiomerically pure by column chromatography. Unexpected NMR observations coupled with DFT calculations allowed the stereochemical assignment of the synthesized adducts. The stereochemical assignment performed in silico was further unambiguously validated by structural X-ray diffraction analysis. Fil: Llompart, David Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Corne, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Suarez, Alejandra Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Spanevello, Rolando Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Echeverría, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Piro, Oscar Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina Fil: Castellano, Eduardo E.. Universidade de Sao Paulo; Brasil. Instituto de Física de São Carlos; Brasil

Two novel aromatic molecules were synthesized via a modified Ullmann coupling starting from a known compound 2,7-diiodofluorenone with carbazole derivatives. These compounds were obtained in very good yields. Due to their fluorophore components, like fluorenone and carbazole, they could be applied as scaffolds for the development of organic materials like dendrimers and polymers. Fil: Mangione, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina Fil: Spanevello, Rolando Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina

An experimental and computational study was conducted to assess the effect of chlorine and bromine substitution in Diels–Alder reactions involving chiral α-halo enones as dienophiles. An important rate enhancement was observed in the case of acyclic dienes, while the use of cyclic dienes resulted in prolonged reaction times and lower yields. DFT calculations suggest that these reactions are governed by finely balanced geometric and electronic features at the TSs.

An appealing inversion in the regiochemical outcome of Diels–Alder reactions between levoglucosenone ( 1 ) and its α-bromo derivative ( 5 ) with isoprene ( 2 ) was studied computationally. Based on different DFT calculations we concluded that both reactions should display the same regioselectivity. This result was further validated experimentally.

The Diels–Alder reaction of the acrylate derived from levoglucosenone with cyclopentadiene was studied under several conditions, in the presence and absence of a Lewis acid. The results showed satisfactory diastereomeric excess and the ratio of cycloadducts was found to depend on the reaction conditions. A reversal in stereoselectivity was observed when EtAlCl 2 or Et 2 AlCl were employed as Lewis acids.

A two-step general approach to a new chiral auxiliary starting from levoglucosenone is reported. The compound is obtained by a [4+2] cycloaddition reaction with anthracene followed by a diastereoselective reduction of the C-2 keto function in high overall yield. The auxiliary has been used as chiral template in an asymmetric Diels–Alder reaction of the corresponding acrylic ester derivative with cyclopentadiene and shown to be efficient for asymmetric induction.

A novel and general approach has been delineated for the enantiomerically pure synthesis of the angularly fused tricyclic system of the pentalenolactone family of compounds. D-Glucose is used as starting material and a diasteroselective Diels-Alder reaction sets the elements for the ring junctions.

The syntheses of new cyclic hexapeptides are described. These peptides potently displace [ 125 I] CGP-23996 (des-Ala 1 , Gly 2 -desamino-Cys 3 [Tyr 11 ]-dicarba 3,14 SRIF) from SRIF receptors on AtT-20 cells. Two of these compounds are of potential value for the isolation of SRIF receptors by affinity chromatography. A key feature in the design was the use of orthogonal protection to provide selective covalent bonding to the solid support.