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Stereodivergent and Protecting‐Group‐Free Synthesis of the Helicascolide Family: A Rhodium‐Catalyzed Atom‐Economical Lactonization Strategy
Author(s) -
Haydl Alexander M.,
Berthold Dino,
Spreider Pierre A.,
Breit Bernhard
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201600632
Subject(s) - stereocenter , rhodium , intramolecular force , chemistry , natural product , catalysis , combinatorial chemistry , stereochemistry , group (periodic table) , enantioselective synthesis , organic chemistry
Natural products of polyketide origin, in particular small‐sized lactones often possess a very broad range of impressive biological activities. An efficient way to demonstrate the concise access to six‐membered lactones was emphasized as part of a stereodivergent and protecting‐group‐free synthesis of all three representatives of the helicascolide family. This strategy features an atom‐economical and highly diastereoselective rhodium‐catalyzed “head‐to‐tail” lactonization by an intramolecular addition of ω‐allenyl‐substituted carboxylic acids to terminal allenes, including the selective construction of a new stereocenter in the newly formed core structures. The excellent selectivities with which the helicascolide precursors were obtained are remarkable, thus resulting in an expeditious and highly efficient natural product synthesis.