A convergent total synthesis of ouabagenin, an aglycon of cardenolide glycoside ouabain, was achieved by assembly of the AB-ring, D-ring and butenolide moieties. The multiply oxygenated cis-decalin structure of the AB-ring was constructed from (R)-perillaldehyde through the Diels-Alder reaction and sequential oxidations. The intermolecular acetal formation of the AB-ring and D-ring fragments, a...

A convergent total synthesis of ouabagenin, an aglycon of cardenolide glycoside ouabain, was achieved by assembly of the AB-ring, D-ring and butenolide moieties. The multiply oxygenated cis-decalin structure of the AB-ring was constructed from (R)-perillaldehyde through the Diels–Alder reaction and sequential oxidations. The intermolecular acetal formation of the AB-ring and D-ring fragments, a...

Current Fused Deposition Modeling (FDM) technologies deposit material as flat layers. The result is a “stair-case” effect on non-vertical or horizontal surfaces, and compromised part strength because of weakness between the laminations. This paper describes a FDM method through which layers of build material are deposited as curved layers following the shape of the part, thus removing the stair...

Oxidative fusion reactions of meso-phenoxazino Ni(ii) porphyrin were found to be temperature dependent, giving rise to either a doubly phenylene-fused product at room temperature or a singly phenoxazine-fused product at 70 °C. The latter was further oxidized to a doubly phenoxazine-fused Ni(ii) porphyrin, which was subsequently converted to the corresponding free base porphyrin and Zn(ii) porph...

Simple syntheses of the benzo-fused 26-membered macrocyclic bischalcone (19E,43E)-2.11.27.36-tetroxaheptacyclo[44.4.0.0(4,9).0(12,17).0(21,26).0(29,34).0(37,42)]pentaconta-1(46),4(9),5,7,12(17),13,15,19,21,23,25,29,31,33,37,39,41,43,47,49-icosaene-18,45-dione (3) and the benzo-fused 13-membered macrocyclic chalcone (19E)-2.11-dioxatetracyclo[19.4.0.0(4,9).0(12,17)]pentacosa-1(25),4(9),5,7,12(17...

The dehydrogenation of a Jet A hydrocarbon mixture was investigated for the production of hydrogen for fuel cell applications. This process differs from steam/partial oxidation reforming of hydrocarbons in that the hydrogen produced is free of CO, and therefore can be used in low temperature fuel cells without further purification. Because of their relative importance with respect to the spectr...

The quinone Diels-Alder (QDA) reaction has considerable synthetic power in terms of introducing structural complexity. As a consequence, the corresponding transform is a worthwhile goal in retrosynthetic analysis and therefore has been implemented as a transform-goal, or long-range, strategy in the LHASA program. The implemented strategy allows LHASA to convert any suitable target containing th...

An unusual polyketide with a new carbon skeleton, lindgomycin (1), and the recently described ascosetin (2) were extracted from mycelia and culture broth of different Lindgomycetaceae strains, which were isolated from a sponge of the Kiel Fjord in the Baltic Sea (Germany) and from the Antarctic. Their structures were established by spectroscopic means. In the new polyketide, two distinct domain...