title: Regiospecific 6-endo-annulation of in situ generated 3,4-dienamides/acids: synthesis of δ-lactams and δ-lactones.
abstract: A novel and efficient method for the construction of α-(1,3-dithiolan-2-ylidene) δ-lactam and δ-lactone rings has been developed. It involves the regiospecific 6-endo-annulation of in situ generated 2-(1,3-dithiolan-2-ylidene)-3,4-dienamides/acids from the dehydrative coupling of α-oxo ketene dithioacetals with tertiary propargyl alcohols promoted by BF3·Et2O. A range of α-(1,3-dithiolan-2-ylidene) δ-lactams and δ-lactones are obtained in good to high yields. In addition, indenes are prepared by using α-acetyl ketene dithioacetal as the precursor.
authors.affiliation: Department of Chemistry, Northeast Normal University, Changchun 130024, PR of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Badru-Deen
authors.initials: BD
authors.lastname: Barry
authors.forename: Haifeng
authors.initials: H
authors.lastname: Yu
authors.forename: Jianquan
authors.initials: J
authors.lastname: Liu
authors.forename: Peiqiu
authors.initials: P
authors.lastname: Liao
authors.forename: Xihe
authors.initials: X
authors.lastname: Bi
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D002384:Catalysis; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D000577:Amides; D007769:Lactams; D007783:Lactones