Dithiolopyranthione Synthesis, Spectroscopy, and an Unusual Reactivity with DDQ

作者：Pimkov Igor V; Nigam Archana; Venna Kiran; Fleming Fraser F; Solntsev Pavlo V; Nemykin Victor N; Basu Partha^*

来源：Journal of Heterocyclic Chemistry, 2013, 50(4): 879-886.

DOI：10.1002/jhet.1715

The bicyclic pyran thiolone tetrahydro-3H-[1,3]dithiolo[4,5-]pyran-2-thione (3a) engages in a highly unusual fragmentation in the presence of DDQ. The pyran thiolone, 3a, was synthesized by chlorination of 3,4-dihydro-2H-pyran (1) followed by condensing with CS2 and NaSH. Reaction of 3a with DDQ generates the isomerized pyran thiolone tetrahydro-3H-[1,3]dithiolo[4,5-]pyran-2-thione (3b) and 4-benzyl-5-(3-hydroxypropyl)-1,3-dithiole-2-thione (4) via a deep-seated rearrangement. The identity of 3b was confirmed by single crystal X-ray analysis: P21/c, a=5.807(9)angstrom, b=12.99(2)angstrom, c=11.445(15), =113.23(6)degrees. Mechanistic experiments and computational insight is used to explain the likely sequence of events in the highly unusual formation of 4. Collectively, these results establish fundamental reactivity patterns for further research in this area.

• 出版日期2013-7