Template-Directed C−H Insertion: Synthesis of the Dioxabicyclo[3.2.1]octane Core of the Zaragozic Acids
journal contributionposted on 27.06.2001, 00:00 by Duncan J. Wardrop, Adriana I. Velter, Raymond E. Forslund
The preparation of (±)-24, a model for the core of the zaragozic acids, is reported. The pivotal reaction in this endeavor is the dirhodium(II)-catalyzed intramolecular C−H bond insertion of 2-diazoacetyl-1,3-dioxane 4, a transformation which generates four of the six stereocenters present in the core structure. A novel method for the diastereoselective synthesis of pyruvic acid acetals was also developed and employed in the preparation of 4 from xylitol derivative 7.