131887-89-3Relevant academic research and scientific papers
[3,3]Sigmatropic ring expansion of cyclic thionocarbonates. Highly stereoselective synthesis of (Z)- or (E)-double bonds by controlling chairlike-boatlike transition states in the [3,3]sigmatropic rearrangement of 8-membered thionocarbonates
Harusawa,Osaki,Fujii,Yoneda,Kurihara
, p. 9433 - 9450 (2007/10/02)
A highly stereoselective synthesis of (Z)- or (E)-double bonds in 10-membered thiolcarbonates (3) was successfully conducted by controlling the chairlike-boatlike transition states in the [3,3]sigmatropic rearrangement of 8-membered thionocarbonates (2). The geometry of the product appeared to be highly dependent on the substituent pattern in the allylic system of the substrates (1). The 10-membered thiolcarbonates (3) were readily converted to (Z)- or (E)-allylic thiolcarbonates (11). Treatment of (Z)-3j or 3i with lithium in liquid ammonia afforded (Z)-trisubstituted or tetrasubstituted olefins (12j and 12i) in high yields.
