title: Efficient and practical synthesis of L-hamamelose.
abstract: An efficient synthetic route of L-hamamelose was successfully accomplished starting from D-ribose. L-Hamamelose was synthesized in 42% overall yield with six reaction steps via a stereoselective Grignard reaction, a stereoselective crossed aldol reaction and a controlled oxidative cleavage of the double bond of a vinyl diol compound. During the oxidative cleavage of the double bond of the vinyl diol compound with osmium tetroxide and NaIO(4), an over-oxidative cleavage of alpha-hydroxyl aldehyde generated from ring opening of the first cleaved product, formyl lactol, did not occur, probably due to the stability of the lactol form. A plausible mechanism for the stereoselective crossed aldol reaction was suggested. The final target compound, L-hamamelose can play a very important role as a chiral building block in synthesizing a wide variety of enantiopure compounds.
authors.affiliation: Laboratory of Medicinal Chemistry, College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Kim
authors.forename: Jin-Ah
authors.initials: JA
authors.lastname: Kang
authors.forename: Hyung-Rock
authors.initials: HR
authors.lastname: Lee
authors.forename: Ah-Young
authors.initials: AY
authors.lastname: Park
authors.forename: Pusoon
authors.initials: P
authors.lastname: Chun
authors.forename: Boeun
authors.initials: B
authors.lastname: Lee
authors.forename: Jungsu
authors.initials: J
authors.lastname: Kim
authors.forename: Jin-Ah
authors.initials: JA
authors.lastname: Kim
authors.forename: Lak Shin
authors.initials: LS
authors.lastname: Jeong
authors.forename: Hyung Ryong
authors.initials: HR
authors.lastname: Moon
mesh_terms: D006601:Hexoses / Q000138:chemical synthesis*; D019906:Nuclear Magnetic Resonance, Biomolecular; D012266:Ribose / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006601:Hexoses; C009758:hamamelose; D012266:Ribose