title: Biomimetic synthesis of acid-sensitive (-)- and (+)-caparrapi oxides, (-)- and (+)-8-epicaparrapi oxides, and (+)-dysifragin induced by artificial cyclases.
abstract: Asymmetric total syntheses of acid-sensitive (-)- and (+)-caparrapi oxides (1) and (+)-8-epicaparrapi oxide (2) from farnesol (10) are achieved using Sharpless-Katsuki epoxidation and Lewis acid-assisted chiral Brønsted acid (chiral LBA)-induced polyene cyclization as key steps. The relative configuration of (+)-dysifragin (4) is determined by a single-crystal X-ray diffraction and its total synthesis is accomplished by the diastereoselective epoxidation of (+)-1. Furthermore, (-)-1 can be directly synthesized from (S)-nerolidol (3) and (R)-LBA with 88% ds by reagent control, which overcame substrate control, while (-)-2 is obtained from (R)-3 and (R)-LBA with >99% ds by the double asymmetric induction.
authors.affiliation: Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Muhammet
authors.initials: M
authors.lastname: Uyanik
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ishihara
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamamoto
mesh_terms: D000143:Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004798:Enzymes / Q000378:metabolism*; D018716:Molecular Mimicry; D010087:Oxides / Q000138:chemical synthesis*; D012717:Sesquiterpenes / Q000138:chemical synthesis*; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D000143:Acids; D004798:Enzymes; D010087:Oxides; D012717:Sesquiterpenes; C505666:dysifragin