Synthesis of lignan aryldihydronaphthalene lactones by cyclization of cinnamyl arylpropiolate esters: revised structure of beta-apopolygamatin.
Unlike arylpropargyl arylpropiolates (e.g., 3) which yield, on heating in xylene, arylnaphthalene type I and type II lactones (4 and 5, respectively) in 1:1 ratio, cinnamyl arylpropiolates (e.g., 7) on heating in DMF gave the aryldihydronaphthalene-2-carboxylic acid lactones (e.g., 8) in excellent yield and regioselectivity. It is suggested that the aryldihydronaphthalene lactone product isolated from the tumor-inhibiting extract of Polygala polygama and previously named beta-apopolygamatin [17] has in fact the structure 1-(3',4'-methylene-dioxyphenyl)-3-hydroxymethyl-7,8-dimethoxy-3,4- dihydro-2- naphthoic acid lactone [18].
Stevenson
R
R
Department of Chemistry, Brandeis University, Waltham, Massachusetts 02254.
Weber
J V
JV
D002934:Cinnamates / Q000737:chemistry*; D004149:Dioxoles / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D007783:Lactones / Q000737:chemistry*; D017705:Lignans; D008031:Lignin / Q000138:chemical synthesis*; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis*
D002934:Cinnamates; D004149:Dioxoles; D004952:Esters; D007783:Lactones; D017705:Lignans; D009281:Naphthalenes; C069238:beta-apopolygamatin; D008031:Lignin