title: Stereoselective C-glycosidation of D-fucose derivatives directed by the protective groups.
abstract: Stereoselectivity in the C-glycosidation of lactones derived from D-fucose by following Kishi's method, which involves the addition of a nucleophile onto a carbohydrate-derived lactone and subsequent reduction of the lactol, was found to be reliant on the nature of the C2 and C3 protective groups. Lactones bearing TBDMS protecting groups selectively afford 1,3-trans products (α anomer), in which the stereoselective outcome is in apparent concordance with Woerpel's model. On the other hand, their benzylated congeners produce the 1,3-cis products (β anomer) as the major diastereoisomers. The latter results suggest an abnormal behavior during the stereoselective nucleophilic substitution at the anomeric position of the benzylated lactones.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, 04510 México, D.F., Mexico.
authors.forename: Omar
authors.initials: O
authors.lastname: Cortezano-Arellano
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, 04510 México, D.F., Mexico.
authors.forename: Camilo A
authors.initials: CA
authors.lastname: Meléndez-Becerra
authors.affiliation: Centro Conjunto de Investigación en Química Sustentable UAEMex-UNAM, carretera Toluca-Atlacomulco Km 14.5, Toluca 50200, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cortés
authors.affiliation: Centro de Investigación de la Facultad de Ciencias Químicas, BUAP, 14 sur esq. San Claudio, San Manuel, 72570 Puebla, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Sartillo-Piscil
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, 04510 México, D.F., Mexico. Electronic address: acordero@unam.mx.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cordero-Vargas
mesh_terms: D005643:Fucose / Q000031:analogs & derivatives* / Q000737:chemistry*; D006031:Glycosylation; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D007783:Lactones; D005643:Fucose
keywords: Carbohydrates; Fucose derivatives; Lactones; Stereoselectivity