title: Stereoselective Alkylation of the Vinylketene Silyl N,O-Acetal and Its Application to the Synthesis of Mycocerosic Acid.
abstract: Stereoselective alkylation of the vinylketene silyl N,O-acetal possessing a chiral auxiliary has been achieved by using activated alkyl halides including allyl iodides, benzyl iodides, and propargyl iodide with Ag(I) ion in the presence of BF3·OEt2. The reaction proceeded to give reduced polyketides in high stereoselectivity. The synthesis of mycocerosic acid, a component of the cell envelope of Mycobacterium tuberculosis, has been accomplished by this methodology. During the synthetic studies, 2-methylbenzimidazole was found to be a bulky proton source which worked in the presence of liquid ammonia.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ieki
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Seijiro
authors.initials: S
authors.lastname: Hosokawa
mesh_terms: D000080:Acetals; D000478:Alkylation; D001562:Benzimidazoles; D020650:Combinatorial Chemistry Techniques; D005227:Fatty Acids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000737:chemistry; D061065:Polyketides / Q000138:chemical synthesis; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D001562:Benzimidazoles; D005227:Fatty Acids; D061065:Polyketides; D012821:Silanes; C032992:mycocerosic acid; C109865:2-methylbenzimidazole