Asymmetrische Synthese von hoch substituierten delta -Lactonen : Synthese der Prelactone B und V, von Simplacton B und von Massoialacton

The asymmetric syntheses of prelactone B und V, simplactone B, massoialactone and of related Delta-lactones were carried out in this work. The RAMP-hydrazone of 2,2-dimethyl-1,3-dioxan-5-one was chosen as starting material for the synthesis of the 4-hydroxy-5,6-alkyl and 4-hydroxy-5-alkyl substituted lactones (prelactones und simplacton B). Key step of this six step synthesis was the hydrogenation of the exo-cyclic double bond of the precursor using homogeneous catalysts. The reduction of the unsaturated lactones using Crabtree´s catalyst led to the desired products, with the right relative configuration (all substituents in trans-position). If Wilkinson´s catalyst was used for the hydrogenation of the precursor of prelactone B, the selective formation of the 5-epimer of prelactone B was observed. The synthesis of (R)-massoialactone could also be achieved starting from the RAMP-hydrazone of 2,2-dimethyl-1,3-dioxan-5-one. The desired carboxyl-functionality was generated via a methylfurfuryl substituent and the deoxygenation of the Alpha,Alpha´-disubstituted dioxanones was carried out using the Barton-McCombie-protocol.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2005

Author dc:creator

• Job, Mareile

Contributors dc:contributor

• Enders, Dieter

• info:eu-repo/classification/ddc/540
• Tetrahydropyranonderivate
• Asymmetrische Synthese
• Hydrazon-Methode
• Chemie
• Prelactone
• SAMP/RAMP-Methode
• Naturstoffsynthese

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123415%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61791