Norbornadiene

About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.

Manufacture of vitamin b6

Abstract: A process for the manufacture of a =:1-1,3-dihydrofuro[ 3,4-c] pyridine (I) 1 which is 4,7-disubstituted with a readily cleavable group (R) involves reacting a bis(3-R- substituted 2-propynyl) ether of the formula (R-C C-CH2)2O (II) with acetonitrile in the presence of a cobalt(I) complex catalyst of the formula XCo(I)Ligl/2 (III), wherein X signifies cyclopentadienyl, acetylcyclopentadienyl, indenyl or phenylborinato and Lig1/2 signifies the cyclooctadiene or norbornadiene ligand (Lig1) or two carbonyl or ethene ligands (Lig2), in an aliphatic, alicyclic or aromatic hydrocarbon solvent, or in excess acetonitrile as the reagent and simultaneously the solvent, or in water alone or in admixture with an ethereal co-solvent, or in a mixture of two or more of the aforementioned types of solvents, at a temperature in the range from about O°C to about 80°C, under light irradiation at wavelengths from about 300 nm to about 800 nm and with as much exclusion of atmospheric oxygen as possible. The so-produced 4,7-di(R)- substituted 6-methyl-1,3-dihydrofuro[3,4-c]pyridine is useful as an intermediate in the multistage process for manufacturing vitamin B6, especially pyridoxine. The invention further concerns the novel bis(3-R'-substituted 2-propynyl) ethers of the formula (R'-C C-CH2)2O (II'), wherein R' signifies a tri(C2-8-alkyl)silyl group, and the novel 4,7- di(R')-substituted 6-methyl-1,3-dihydrofuro [3,4-c] pyridines.

A novel and efficient synthesis of 9-(c-4, t-5-bishydroxymethylcyclopent-2-en-r-1-yl)-9H-adenine (BCA) having anti-HIV activity from norbornadiene

Abstract: 9-(c-4, t-5-Bishydroxymethylcyclopent-2-en-r-1-yl)-9H-adenine (BCA: 1), a novel carbocyclic nucleoside having significant anti-HIV activity, has been synthesized from norbornadiene

Pentacyclic hydrocarbon compound and halogenated pentacyclic hydrocarbon compound, and preparation processes thereof

Abstract: A process for the preparation of the compound of the formula ##STR1## comprising dimerizing norbornadiene in the presence of N-methylpiperidine and a combined catalyst of (1,5-cyclooctadiene)(1,3,5-cyclooctatriene)-ruthenium and N,N-dimethylacrylamide.

Density functional study of the retrocyclization of norbornadiene and norbornene catalyzed by Fe(

Abstract: In the presence of Fe(+) catalyst, the retro Diels-Alder reaction of norbornadiene (NBD) is predicted to be stepwise with an activation barrier of 18.8 kcal/mol, which is 3.1 kcal/mol lower than the concerted retro reaction. For norbornene (NBN), the Fe(+)-catalyzed retro reaction is also calculated to be stepwise with an activation barrier of 24.9 kcal/mol, which is 8.5 kcal/mol lower than the uncatalyzed stepwise reaction but 3.8 kcal/mol higher than the concerted reaction. The intermediates from the NBD and NBN retro Diels-Alder reactions, C(5)H(6)FeC(2)H(2)(+) and C(5)H(6)FeC(2)H(4)(+), are predicted to have low activation barriers for ligand-to-ligand hydrogen transfers (through an iron-hydrido intermediate) to form CpFeC(2)H(3)(+) and CpFeC(2)H(5)(+) and, ultimately, vinyl- and ethyl-substituted cyclopentadiene-iron complexes, respectively. In contrast to FeC(2)H(2)(+) and FeC(2)H(4)(+), the lowest-energy pathways on the C(5)H(6)FeC(2)H(2)(+) and C(5)H(6)FeC(2)H(4)(+) potential energy surfaces involve only one multiplicity (quartet). The C(2)H(2) and C(2)H(4) complexes of CpFe(+) and C(5)H(6)Fe(+) are compared.