Asymmetric induction mediated by an N–N chiral axis
Abstract
Reaction of 3-methylpentane-2,4-dione 11 with N-acetoxyaminoquinazolinone 6 gives an isolable enol 12, which is chiral by virtue of the high barrier to rotation around its N–N bond; protonation of the double bond occurs in glacial acetic acid to give a single diastereoisomer of keto-amide 13.