アミノ酸を用いる分子内不斉アルドール反応のエナンチオ選択性と新規双環性キラル素子の開発

抄録

Hajos-Parrish-Eder-Sauer-Wiechert reaction has been well-kwown as a successful intramolecular asymmetric aldol reaction mediated by an amino acid to synthesize Wieland-Miescher ketone derivatives. However, there have been few reports to apply this reaction to construct a medium ring in an enantioselective fashion. We report here a detailed study to assess the enantioselectivity of the amino acid-mediated intramolecular asymmetric aldol reaction of a 1,3-cycloheptanedione derivative to construct a new chiral building block. The cyclizations were mediated by a series of L-amino acids in the presence of an acid co-catalyst. Strikingly, the process was characterized by an inversion of enantioselectivity when compared to a similar reaction involving the 1,3-cyclohexanedione counterpart.

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