title: Synthesis of CH2-linked alpha(2,3)sialylgalactose analogue: on the stereoselectivity of the key Ireland-Claisen rearrangement.
abstract: A CH 2 -linked alpha(2,3)sialylgalactose analogue was efficiently synthesized using an Ireland-Claisen rearrangement, which was developed recently by our group for constructing a CF 2 -sialoside. The reaction conditions of the rearrangement were optimized for alpha-stereoselective formation of the CH 2 -sialoside. On the basis of the observed temperature effects, the origin of the stereoselectivity of the Ireland-Claisen rearrangement is discussed. Moreover, reconstruction of the 2alpha-hydroxyl group on the galactose unit of the rearrangement product was achieved by means of stereoselective dihydroxylation and deoxygenation.
authors.affiliation: RIKEN, Hirosawa, Wako 351-0198, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Watanabe
authors.forename: Go
authors.initials: G
authors.lastname: Hirai
authors.forename: Marie
authors.initials: M
authors.lastname: Kato
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hashizume
authors.forename: Taeko
authors.initials: T
authors.lastname: Miyagi
authors.forename: Mikiko
authors.initials: M
authors.lastname: Sodeoka