title: [5C + 1N] annulations: two novel routes to substituted dihydrofuro[3,2-c]pyridines.
abstract: Two novel routes based on [5C + 1N] annulations for the synthesis of 2,3-dihydrofuro[3,2-c]pyridines are described. Ammonium acetate (NH(4)OAc) is used as an ammonia source in both routes. The first route utilizes 1-acyl-1-[(dimethylamino)alkenoyl]cyclopropanes as a five-carbon 1,5-bielectrophilic species and combines the [5C + 1N] annulation and regioselective ring-enlargement of cyclopropyl ketone into one pot, whereas the second route utilizes 3-acyl-2-[(dimethylamino)alkenyl]-4,5-dihydrofurans as the five-carbon synthons, which involves a sequential intermolecular aza-addition, intramolecular aza-nucleophilic addition/elimination, and dehydration reaction.
authors.affiliation: Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Huang
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Yongjiu
authors.initials: Y
authors.lastname: Liang
authors.forename: Dewen
authors.initials: D
authors.lastname: Dong
mesh_terms: D002244:Carbon / Q000737:chemistry; D006865:Hydrogenation; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D011725:Pyridines; D002244:Carbon; D009584:Nitrogen