28465-80-7Relevant academic research and scientific papers
Zwitterion-accelerated -Sigmatropic Rearrangements and -Sigmatropic Rearrangements of Sulphoxides and Amine Oxides
Hwu, Jih Ru,Anderson, Denise A.
, p. 3199 - 3206 (2007/10/02)
The effect of a zwitterionic moiety on -sigmatropic rearrangements has been studied.The allyl vinyl sulphoxide 5 underwent a -sigmatropic rearrangement at 23 deg C under neutral conditions to give the thione S-oxide 6 (96percent).This rearrangement (k1 = 1.56 +/- 0.04 x 10-1 h-1) was 45 times faster than conversion of the corresponding sulphide 3 into the thione 4 ( k1 = 3.5 +/- 0.1 x 10-3 h-1).At 23 deg C, the sulphoxide 7 also rearranged to give a mixture of (E)- and (Z)-thial S-oxide 8 (90percent).These experiments showed that the accelerating effect of the charges in the sulphoxide, a zwitterionic moiety, did not cancel out.Instead, the sulphoxide moiety significantly facilitated the -sigmatropic rearrangement.In the thermolysis of hexa-1,5-dienes with a zwitterionic moiety attached to the C-3 position ( e.g., 9 and 24), -sigmatropic rearrangements occurred.The conversion of the allyl sulphoxide 21 into the corresponding sulphenate ester 22 by a process was used as the key step in a total synthesis of yomogi alcohol 23, a biologically active monoterpenoid.
