title: Synthesis of 3-Deoxy-L-ketohexoses through Group Transfer.
abstract: A practical method for the synthesis of 3-deoxy-L-ketohexoses is described. Both D- and L-ketohexoses can be transformed into rare 3-deoxy-L-ketohexoses in six steps through a group transfer process. The key step involves a radical cyclized onto a carbonyl group, followed by a fragmentation reaction, eventually resulting in the group transfer of an α-oxy carbonyl group. The process involves tin-free and environmentally benign radical conditions (TTMSS/AIBN/toluene). The acyclic form of 3-deoxy-L-fructose was prepared in only three steps from the inexpensive starting material, D-fructose. A further modification by preparing a dithioacetal derivative was accomplished, which could serve as a convenient sugar synthon for further synthetic applications. Removal of the dithioacetal protecting group results in the formation of the rare 3-deoxy-L-fructose in a total yield of 42%. This methodology could be further extended to the synthesis of other deoxy-L-ketohesoses, such as 3-deoxy-L-sorbose.
authors.affiliation: Department of Chemistry, Fu Jen Catholic University , 510 Zhongzheng Road, Xinzhuang District, New Taipei City 24205, Taiwan Republic of China.
authors.forename: Tai-Ni
authors.initials: TN
authors.lastname: Lu
authors.affiliation: Department of Chemistry, Fu Jen Catholic University , 510 Zhongzheng Road, Xinzhuang District, New Taipei City 24205, Taiwan Republic of China.
authors.forename: Che-Chien
authors.initials: CC
authors.lastname: Chang