Synthetic studies on the molybdenum cofactor: Total synthesis of pterindithiolenes by direct dithiolene formation from suitable pterin alkynes

ABSTRACT

A novel, efficient total synthesis of a series of pterindithiolenes (15, 16, 17 and 18) [(5,6-dihydro-[1,4]dithiin or 6,7-dihydro-5H-[1,4]dithiepin systems respectively for six and seven membered dithiolenes] has been reported. The six membered quinoxaline thioketal 9 and seven membered quinoxaline dithiolene 11 have also been synthesized from quinoxaline acetylenic alcohol 5 and the corresponding acetylenic ketone 10 respectively. The synthesis of five membered pterin thioketals 12 and 13 along with the conversion of 13 to the dithiolene 14 by the reaction with NBS is also reported.

GRAPHICAL ABSTRACT

KEYWORDS:

• Moco
• six and seven membered pterindithiolenes
• six membered quinoxaline dithiolenes

Acknowledgement

We also thank DST, India for the financial support. A. C. M thank UGC, India for research fellowship and we appreciate mass spectral help from Professor Thomas Schrader, Universitätsstrasse 5, 45117 Essen, Germany .We also thank TCG Life Science Ltd, Kolkata for some NMR spectral support.