摘要

(R)-(+)-Carolinic acid was prepared in seven steps and 59% yield from inexpensive benzyl L-lactate, the configuration of which was inverted by a Mitsunobu reaction with trifluoroacetate. The resulting benzyl D-lactate was cyclised by a domino addition-Wittig alkenation reaction with Ph3PCCO. The product tetronic acid was acylated with a second equivalent of this ylide to give a 3-acylylidenetetronic acid, which was olefinated directly with tert-butyl glyoxylate. The product alkene was hydrogenated and deprotected to afford pure crystalline (R)-(+)-carolinic acid, which proved inactive against Staphylococcus aureus and Escherichia coli mutant D21f2.

  • 出版日期2016-12

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