Tandem Sonogashira cross-coupling and heteroannulation of 7-hydroxy-8-iodo-2-(trifluoromethyl)chromen-4-one with terminal acetylenes afforded the 8-carbo–substituted 2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-ones 2a–i. The latter were reacted with methyl mercaptoacetate in the presence of triethylamine to afford the corresponding 7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one derivatives 3a–i. The structures of the prepared compounds were characterized using a combination of NMR (¹H-, ¹³C & ¹⁹F-), IR and mass spectroscopic techniques, and confirmed by single X-ray crystal structures of 8-(3-fluorophenyl)-2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-one (2b) and 2-phenyl-7-(trifluoromethyl)-7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one (3a). The highlight of this investigation is the conversion of 2-(trifluoromethyl)–substituted 4H-furo[2,3-h]chromen-4-ones into trifluoromethyl–substituted thienoangelicin analogues.

串联Sonogashira交叉偶联7-羟基-8-碘-2-（三氟甲基）铬-4--4-异环末端乙炔，得到8-碳取代的2-（三氟甲基）-4 H-呋喃[2,3] - ħ ]苯并吡喃-4-酮2A -我。后者在三乙胺的存在下与巯基乙酸甲酯反应，得到相应的7,8-二氢-5 H-呋喃[2,3- h ] thieno [2,3 - c ] chromen-5-one衍生物3a – i。使用NMR（¹ H-，¹³ C和¹⁹F-），红外光谱和质谱技术，并通过8-（3-氟苯基）-2-（三氟甲基）-4 H-呋喃[2,3- h ] chromen-4-one的单X射线晶体结构证实（2b）和2-苯基-7-（三氟甲基）-7,8-二氢-5 H-呋喃[2,3- h ] thieno [2,3 - c ] chromen-5-one（3a）。这项研究的重点是将2-（三氟甲基）取代的4 H -furo [2,3 - h ] chromen-4-ones转化为三氟甲基取代的硫代Angelelicin类似物。