First isolation of eclipsed vic-disulfoxide: 7,8-dithiabicyclo[4.2.1]nona-2,4-diene 7-exo,8-exo-dioxide.
[reaction: see text] The oxidation of 7,8-dithiabicyclo[4.2.1]nona-2,4-diene 7-exo-oxide with dimethyldioxirane (DMD) provided the 7-exo-8-exo-dioxide, the structure of which was determined by X-ray crystallography [S-S 2.341(2) A and 90 degree angle O-S-S-O 4.1(3) degrees ]. The exo attack of DMD to give the exo,exo-dioxide was kinetically more favorable than the endo attack to give the endo,exo-dioxide. DFT calculations showed that the exo,exo-dioxide is thermodynamically more stable than the other stereoisomers.
Ishii
Akihiko
A
Department of Chemistry, Faculty of Science, Saitama University, Sakura-ku, Saitama, Saitama 338-8570, Japan. ishiiaki@chem.saitama-u.ac.jp
Kashiura
Satoshi
S
Oshida
Hideaki
H
Nakayama
Juzo
J