title: A simple but remarkably effective device for forming the C8-C14 polycyclic ring system of halichondrin B.
abstract: A simple device consisting of two ion-exchange columns, two alumina-based filters, and a pump (Figure 1) was assembled to form the C8-C14 polycyclic ring system present in the halichondrin B class of marine natural products. The effectiveness of this device was tested for three substrates. In each case, the desired polycyclic ketal 3, 5, or 7 was obtained almost quantitatively in a single operation.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Namba
authors.forename: Hyuk-Sang
authors.initials: HS
authors.lastname: Jun
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kishi
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000818:Animals; D003500:Cyclization; D004988:Ethers, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D018942:Macrolides; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011161:Porifera / Q000737:chemistry; D013237:Stereoisomerism; D000095662:Polyether Polyketides
chemical_list: D000447:Aldehydes; D004988:Ethers, Cyclic; D007659:Ketones; D018942:Macrolides; C070519:halichondrin B; D000095662:Polyether Polyketides