Expedient approach to 6-bromo-2-isopropylidenecoumaranone, a potential intermediate for the synthesis of TMC-120B, pseudodeflectusin, and Their congeners
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Date
2016-05-17
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
Description
A straightforward approach toward 6-bromo-2-isopropylidenecoumaranone, a potential intermediate toward alkaloid TMC
120-B, pseudodeflectusin, and other natural products, was reported. The synthetic sequence involved the reaction of
3-bromosalicylaldehyde with chloroacetone and cyclization of the resulting ether to a 2-acetylcoumaranol intermediate. This
was followed by sequential methyl Grignard addition and Jones’ oxidation to the corresponding coumaranone, which was
dehydrated to the final product with the methanesulfonyl chloride/pyridine reagent. The protection of the coumaranol as the
corresponding THP-ether resulted in improved product yields.
Keywords
6-Bromo-2-isopropylidenecoumaranone, TMC-120B, Pseudodeflectusin, Natural Product Synthesis, Prolinemediated Cyclization