title: Synthetic and novel biocatalytic resolution studies on (+/-)-5/6/7-acetoxy-4-aryl-3,4-dihydrocoumarins.
abstract: Eleven (+/-)-5/6/7-acetoxy-4-aryl-3,4-dihydrocoumarins have been synthesised in two steps starting from the coupling of cinnamic acid/substituted cinnamic acid with appropriate phenols, followed by acetylation in 50-83% overall yields. All hydroxy- and acetoxycoumarins were unambiguously identified on the basis of their spectral data. Candida antarctica lipase-catalysed deacetylation of these racemic acetoxydihydrocoumarins in dioxane occurred with moderate enantioselectivity. This is one of the rare examples of resolution using phenolic ester moiety as a remote handle for chiral recognition by a lipase.
authors.affiliation: Bioorganic Laboratory, Department of Chemistry, University of Delhi, -110 007, Delhi, India.
authors.forename: Ishwar
authors.initials: I
authors.lastname: Singh
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Prasad
authors.forename: Ajendra K
authors.initials: AK
authors.lastname: Sharma
authors.forename: Rajendra K
authors.initials: RK
authors.lastname: Saxena
authors.forename: Carl E
authors.initials: CE
authors.lastname: Olsen
authors.forename: Ashok L
authors.initials: AL
authors.lastname: Cholli
authors.forename: Lynne A
authors.initials: LA
authors.lastname: Samuelson
authors.forename: Jayant
authors.initials: J
authors.lastname: Kumar
authors.forename: Arthur C
authors.initials: AC
authors.lastname: Watterson
authors.forename: Virinder S
authors.initials: VS
authors.lastname: Parmar
mesh_terms: D000818:Animals; D002175:Candida / Q000201:enzymology; D002384:Catalysis; D002855:Chromatography, Thin Layer; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D003640:Dealkylation; D004146:Dioxanes / Q000138:chemical synthesis; D008049:Lipase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D020799:Pancrelipase / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism; D013552:Swine
chemical_list: D003374:Coumarins; D004146:Dioxanes; D020799:Pancrelipase; D008049:Lipase