title: Synthesis of the spiroiminal moiety of marineosins A and B.
abstract: A model for the spiroiminal moiety of marineosins A and B was prepared starting from methylvalerolactone. Addition of vinylmagnesium bromide, protection of the alcohol, and reaction of the vinyl ketone with a protected pyrrole-2-carbonitrile N-oxide gave an isoxazoline. Hydrogenolysis of the N-O bond with Raney nickel gave a keto imine that cyclized to a hemi-iminal. O-Methylation, acid-catalyzed cleavage of the TES group and spiroiminal formation, and deprotection completed a seven-step synthesis.
authors.affiliation: Department of Chemistry MS 015, Brandeis University, Waltham, Massachusetts 02454-9110, USA.
authors.forename: Xiao-Chuan
authors.initials: XC
authors.lastname: Cai
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Wu
authors.forename: Barry B
authors.initials: BB
authors.lastname: Snider
mesh_terms: D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D011758:Pyrroles; D013141:Spiro Compounds; C543079:marineosin A; C543080:marineosin B