J. Am. Chem. SOC.1983, 105, 5700-5701
5700
Acknowledgment. This work was supported by the Ministry of Education of Japan under a special research project. We thank Dr. Isao Saito for his helpful suggestions.
A
Supplementary Material Available: Listings of atomic coordinates and thermal parameters in crystalline l g (3 pages). Ordering information is given on any current masthead page.
B
lescence or broadening of the corresponding 'H N M R (80 MHz) signals was not observed even at 78.0 'C, indicating that energy barriers to rotation of the tert-butyl group and to the process A i B are pretty high.7 The stereochemistry of l g (Figure 1) was determined by X-ray crystallography." The molecule situates on a crystallographic mirror plane. The O(2) atom is located in either of two positions that deviate by 0.68 8, from the mirror plane. The lengths of two 0-0 bonds are 1.36 1 and 1.428 A, respectively, and two C-0 bonds are 1.490 and 1.497 A, respectively. The 0-0-0 angle of 113.3' is smaller than the value for ozone (116').Ib The calculated value for the unsubstituted 1,2,3-trioxolane is 104.4 1.6'.12 The fact that the C(9)-C(8)-C(7) angle is larger than the C(2)4(3)
