10.1002/chem.202004004
Chemistry - A European Journal
COMMUNICATION
Assembly of the targeted natural products
crops“). We thank Prof. Matthias Weil for X-ray diffraction
experiments. The X-ray Centre of TU Wien is acknowledged for
providing access to the X-ray diffractometer.
Aminoesters
2
and
3
were alkylated under reductive
. A smooth reaction was
conditions (NaCNBH3) with aldehyde
1
achieved in both instances giving 83% and 80% of dimeric
amines 22 and 24 upon chromatographic purification at
decent scale. Attachment of a Boc protecting group was
realized in high yield (Boc2O, THF) and the resulting
carbamates 23 and 25 proved to be suitably stable storage
compounds. The dimeric compounds 23 and 25 now enter the
second stage of diversification towards the four
phytosiderophores each with a 2’-hydroxy and 2’-deoxy-
structure, respectively. The olefin was cleaved by ozonolysis
yielding aldehydes 26 and 27 which were subsequently
treated with one of the four respective western building
Keywords: micronutrients • mugineic acid • natural products •
phytosiderophores • total synthesis
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Further work on fully assembled 13C2-labelled versions of
compounds I-VIII using the presented strategy as well as
development towards scale up (gram-scale) of the avenic acid
and mugineic acid syntheses and other PS are currently
ongoing in our laboratories and will be reported in due time.
Conflicts of interest
There are no conflicts to declare
Acknowledgements
This work was supported by the European Research Council
(ERC-StG-801954
“Wanted:
Micronutrients!
Phytosiderophore-mediated acquisition strategies in grass
4
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