Sopanat KongsriprapanChutima KuhakarnPramchai DeelertpaiboonKanda PanthongPatoomratana TuchindaManat PohmakotrVichai ReutrakulMahidol UniversityPrince of Songkla University2018-06-112018-06-112012-05-28Pure and Applied Chemistry. Vol.84, No.6 (2012), 1435-144313653075003345452-s2.0-84861362002https://repository.li.mahidol.ac.th/handle/20.500.14594/13916The enantioselective synthesis of a naturally occurring pyranonaphthoquinone isolated from a Thai endemic plant, Ventilago harmandiana, has been achieved. L-Rhamnose and gallic acid were used as the starting materials. A new C-1-glycosidation of L-rhamnal with trimethyl aluminum in the presence of a catalytic amount of ytterbium(III) triflate was developed. A new reagent, PhSCF 2 H/SnCl 4 , for the formylation of partially deactivated and hindered aromatic compounds has been introduced. Phenylthiophthalide was used efficiently as a cycloannulating agent in the Hauser cycloannulation reaction, employing slightly excess lithium t-butoxide as a base with a catalytic amount of lithium chloride. The synthetic route developed is applicable for the synthesis of other analogues with substituents at the aromatic and pyran rings. © 2012, IUPAC.Mahidol UniversityChemical EngineeringChemistryArticleSCOPUS10.1351/PAC-CON-11-08-24