title: A chiron approach to the total synthesis of (+)-aculeatin D.
abstract: A synthesis of natural aculeatin D has been achieved, with the key stereogenic centers taken from inexpensive and readily available D-xylose. In elaboration of D-xylose into a desired form readily applicable in synthesis a previously misinterpreted and overlooked abnormal selectivity in hydroxyl protection was noticed and exploited. Protocols were developed for monotosylation of a triol insoluble in CH2Cl2 and "freezing" the less stable isomer (aculeatin D) at the PIFA-mediated oxidative spirocyclization, respectively. An unexplained deprotonation at a benzyl protecting group by a thermodynamically more stable dithiane carbanion in the literature was also addressed.
authors.affiliation: State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Zhen
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.forename: Yikang
authors.initials: Y
authors.lastname: Wu
mesh_terms: D008968:Molecular Conformation; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014994:Xylose / Q000737:chemistry*
chemical_list: C436886:1,7-dioxa-dispiro(5.1.5.2)pentadeca-9,12-dien-11-one; D013141:Spiro Compounds; D014994:Xylose