SYNTHESIS OF 3,7-DISUBSTITUTED 9-THIATRICYCLO[3.3.1.0(3,7)]NONANE-1,5-DITHIOL DERIVATIVES AND CRYSTAL-STRUCTURE OF TETRAMETHYL NANTHRO[9,10-A]PENTALENE-1,2,4,4A-TETRACARBOXYLATE
W. Dolling et al., SYNTHESIS OF 3,7-DISUBSTITUTED 9-THIATRICYCLO[3.3.1.0(3,7)]NONANE-1,5-DITHIOL DERIVATIVES AND CRYSTAL-STRUCTURE OF TETRAMETHYL NANTHRO[9,10-A]PENTALENE-1,2,4,4A-TETRACARBOXYLATE, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (11), 1998, pp. 2647-2650
A simple and efficient approach to the 9-thiatricyclo[3.3.1.0(3,7)]non
ane ring system (5) has been found by treating cis-bicyclo[3.3.0]octan
e-3,7-diones (1) with Lawesson's reagent or phosphorus pentasulfide. W
hen dione 1 is treated with Lawesson's reagent tetramethyl ydrophenant
hro[9,10-a]pentalene-1,2,4,4a-tetracarb oxylate (6) is obtained as a b
y-product as shown by X-ray structural analysis.