Racemic [(±)-4-isopropyl-1-methyl-7-oxa-cis-bicyclo[4.3.0]non-4-en-8-one] and optically active δ,ε-unsaturated lactones [(-)-(1R,6R)-4-isopropyl-1-methyl-7-oxabicyclo[4.3.0]non-4-en-8-one and (+)-(1S,6S)-4-isopropyl-1-methyl-7-oxabicyclo[4.3.0] non-4-en-8-one)] with the p-menthane system were obtained and their odoriferous properties were evaluated. Biotransformations of the racemic lactone wit...

In the structure of the binuclear title compound, [Cd2(C6H13N2)2Cl6], two Cd(II) atoms are bridged by two Cl(-) ligands, defining a centrosymmetric Cd2Cl2 motif. Each metal cation is additionally coordinated by two Cl(-) ligands and the N atom of a protonated 1,4-di-aza-bicyclo-[2.2.2]octane (H-DABCO)(+) ligand, leading to an overall trigonal-bipyramidal coordination environment with one of the...

selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. this catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...

In the title salt C6H14N2 (2+)·2C7H4ClO2 (-), two 3-chloro-benzoate (3CBA) anions are bridged by one diprotonated 1,4-di-aza-bicyclo-[2.2.2]octane-1,4-diium (H2DABCO(2+)) dication through N-H⋯O hydrogen bonds. In this way, a trimeric unit is generated, in which the mean planes of the two 3CBA anions are twisted with respect to each other by a dihedral angle of 59.87 (9)°. The trimeric units are...

Due to the profound extent to which natural products inspire medicinal chemists in drug discovery, there is demand for innovative syntheses of these often complex materials. This article describes the synthesis of tricarbocyclic natural product architectures through an extension of the enantioselective Birch-Cope sequence with intramolecular Friedel-Crafts alkylation reactions. Additionally, pa...

all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13) and all-endo-5-amino-6-(hydroxymethyl)bicyclo[2.2.2]octan-2-ol (10) were prepared via dihydro-1,3-oxazine or g-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2). Ring closure of b-amino ester 4 resulted in tricyclic pyrimidi...

The gradient geometry-optimization procedure is reformulated in terms of redundant internal coordinates. By replacing the matrix inverse with the generalized inverse, the usual NewtonRaphson-type algorithms can be formulated in exactly the same way for redundant and nonredundant coordinates. Optimization in redundant coordinates is particularly useful for bridged polycyclic compounds and cage s...

A highly efficient catalyst system assembled from enantiomerically pure diaminocyclohexane and Ni(OAc)(2) is, for the first time, used to catalyze the cascade Michael-Henry reaction of various diones and substituted nitroalkenes. A series of polyfunctionalized bicyclo[3.2.1]octane derivatives containing four stereogenic centers are prepared with excellent enantioselectivities (up to >99% ee) an...