Convenient entry to C2 and C3-substituted gulono-γ-lactone derivatives from L-ascorbic acid

ORGN 152

Bruce J. Heyen, bruceh@tabor.edu, Department of Chemistry, Tabor College, 400 S. Jefferson, Hillsboro, KS 67063 and Kandatege Wimalasena, kandatege.wimalasena@wichita.edu, Department of Chemistry, Wichita State University, Wichita, KS 67260.
Chiral C2- and C3-functionalized aldono-1,4-lactone derivatives derived from L-ascorbic acid can be valuable intermediates in the synthesis of pharmacologically active agents. The synthesis of a series of 5,6-O-isopropylidene-2-allyl-3-keto-L-galactono-γ-lactone and 5,6-O-isopropylidene-3-allyl-2-keto-L-galactono-γ-lactone derivatives can be accomplished from the thermal Claisen rearrangement of the corresponding 3-O- and 2-O-allyl derivatives of 5,6-O-isopropylidene-L-ascorbic acid, respectively, followed by stereospecific reduction to the corresponding alcohols. In addition, 2-alkyl-3-amino and 3-alkyl-2-amino-L-galactono-γ-lactones are also synthesized from reductive amination of the C3- and C2-keto groups of the aforementioned isopropylidene derivatives of ascorbic acid.