The Diels-Alder Approach towards Cannabinoid Derivatives and Formal Synthesis of Tetrahydrocannabinol (THC)

Based on the Diels-Alder reaction of vinylchromenes with electron-poor dienophiles, we developed a strategy for the synthesis of tetrahydrocannabinol derivatives. Substituted vinyl chromenes could be converted with several dienophiles to successfully isolate several complex molecules. These molecules already contain the cannabinoid-like base structure and further processing of one such derivative led to a precursor of Delta(9)-tetrahydrocannabinol. The most challenging step towards this precursor was an epoxidation step that was ultimately achieved via dimethyl dioxirane.Peer reviewe

The Diels‐Alder Approach towards Cannabinoid Derivatives and Formal Synthesis of Tetrahydrocannabinol (THC)

Abstract Based on the Diels‐Alder reaction of vinylchromenes with electron‐poor dienophiles, we developed a strategy for the synthesis of tetrahydrocannabinol derivatives. Substituted vinyl chromenes could be converted with several dienophiles to successfully isolate several complex molecules. These molecules already contain the cannabinoid‐like base structure and further processing of one such derivative led to a precursor of Δ9‐tetrahydrocannabinol. The most challenging step towards this precursor was an epoxidation step that was ultimately achieved via dimethyl dioxirane

Duennschicht-Solarzellen aus kristallinem Silizium Abschlussbericht

Activities under the project covered all the processes involved in the fabrication of a crystalline silicon thin-film solar cell applying the high-temperature method, so that R and D work was carried out from testing of materials suitable for the dielectric and semiconductive layers required, development of the process sequences for fabrication of the solar cells, simulation and optimisation of the cell design through to final characterisation of the thin films and solar cells. Several cell designs were tested in parallel for intercomparison. Several high-temperature resistant materials were tested for their suitability to serve as substrate materials.The final project report presents the basic research work and studies on the physical and technological aspects of the crystalline thin-film solar cell as well as the major results of specific development work. The report shows that significant progress could be achieved. The efficiencies of all solar cell designs developed under the project are between 9 and 11%, including those using substrate materials easily available in industry, and it could be demonstrated that the solar cells are equal in potential to the wafer-based silicon cell. (orig./CB)Es wurden alle wesentlichen Teilprozesse, die fuer die Entwicklung einer kristallinen Silicium Duennschicht-Solarzelle nach dem Hochtemperaturverfahren wichtig sind, bearbeitet. Der Projektrahmen reichte von der Materialentwicklung fuer die dielektrischen und halbleitenden Schichten ueber die Entwicklung der Solarzellenprozessschritte, die Simulation und Optimierung des Zellendesigns bis zur Charakterisierung von Schichten und Solarzellen. Dabei wurden mehrere verschiedene Zellentypen parallel untersucht und miteinander verglichen. In einer Studie wurden verschiedene hochtemperaturfeste Materialien auf ihre Eignung als Substrate hin untersucht. In dem hier vorgelegten Abschlussbericht werden die erarbeiteten Grundlagen zur Physik und Technologie der kristallinen Duennschicht-Solarzelle sowie die wichtigsten Ergebnisse der Einzelentwicklungen dargestellt. Der Bericht zeigt, dass auf dem Gebiet der kristallinen Si-Duennschicht-Solarzelle wichtige Fortschritte erzielt werden konnten. Fuer alle entwickelten Zellendesigns wurden, auch auf industrierelevanten Substraten, Wirkungsgrade zwischen 9 und 11% erreicht und es konnte gezeigt werden, dass das Potential dieser Zellen dem der waferbasierenden Siliciumzelle gleichkommt. (orig.)Available from TIB Hannover: F98B2009+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Angewandte Solarenergie - ASE GmbH, Alzenau (Germany)DEGerman