6967
I -
I/
I
il
x
Figure 1. exo-Norbornenol: trace A, R = D ; 22 mol Eu(DPM)&CI,; B, R = H; 22 mol Eu(DPM)~-CCI,; c , R H; CC14. Nortricyclenone: trace D (Vb), R 1 = D; R = H; 22 mol % Eu(DPM)3CCI4; E (Va), R1 = H; R = D; 22 mol Eu (DPM)3-CC14; G, R 1 = R = H; CCl4. Eu(DPM)~-CCI~;F, R1 = R = H; 22 mol
of the resulting spectrum (Figure I, trace E) shows that deuterium in Va is located exclusively at the 5-endo position. The isomeric 5-ex0 deuterated ketone Vb was prepared from the.known acetate IVc,l0 and comparison of the spectra of Va and Vb confirms our spec-
IVa
Va
=
Both Ia and IIa are reduced by sodium borodeuteride retention of stereochemistry12 and strucwith >97 ture. The high specificity of reduction is inconsistent with a mechanism involving long-lived radical intermediates, as proposed for reduction of the mercury analogs of I and 11.' Our results are consistent with an alternate interpretation involving initial formation of RPdH followed by concerted collapse to R H and palladium metal. l 3 Acknowledgment. We thank the donors of the Petroleum Research Fund, administered by the American Chemical Society, for support of this research. per cent do species corresponds to the isotopic distribution of the commercial deuterated reagents NaBD4 and DOAc used in our work. (12) Predominant retention of stereochemistry (per cent unspecified) has also been observed in the reduction of methoxydicyclopentadienylpalladium chloride dimer by Stille and (13) A nonradical bimolecular mechanism is also conceivable, and has some analogy: G . M. Whitesides, J. San Filippo, Jr., E. R. Stredronsky, and C. P. Casey, J . Amer. Chem. Soc., 91, 6542 (1969). * Address correspondence to this author.
OAc IVC
Edwin Vedejs,* Mary F. Salomon
&D H Vb
Department of Chemistry, University of Wisconsin Madison, Wisconsin 53706 Received August 24,1970
tral and stereochemical assignments. Exchange of Olefins with Oxymercurials (10) S. J. Cristol, T. C. Morill, and R. A. Sanchez, J . Org. Chem., 31, 2719 (1966), and references therein. ( 1 1) Mass spectral analysis indicates the following distribution of deuterium, confirmed by nmr integration: IIIa, 7 % do, 9 2 Z d1, 1 % dz; Va, 9.5% do, 90% dt, OSZ dz: Vb, 6.5% do, 92% d1, 1.5% dz. The
Sir: We have found that oxymercurial ions (abbreviated Hg(Ol)OH+), formed by reactions of olefins with merCommunications to the Editor
6968 Table I. Summary of Kinetic Data a t 25" ks', M-' 01A Ethylene Ethylene Propylene Propylene 1-Butene Isobutylene cis-2-Butene cis-2-Butene cis-2-Butene cis-2-Butene trans-?.-Butene trans-2-Butene trans-2-Butene Cyclohexene Cyclohexene Cyclohexene 2-Methyl-lpropen-3-01 2-Methyl- 1propen-3-01 . .
01B
k 4 , M-' sec-I
1-Hexen-6-010 2-Methyl-1-propen-3-01 1-Penten-5-ob 2-Methyl-1-propen-3-01 1-Penten-5-ob 1-Penten-5-ob 1-Penten-5-ola 1-Hexen-6-010 2-Methyl- 1-propen- 3-01 1-Buten-4-01 1-Penten-5-01. 1-Hexen-6-01. 1-Buten-4-01 1-Hexene-6-01. 2-Methyl-1-propen-3-01 1-Butene-4-01 l-Pentene-5-ola
x -5 x 8.5 x 7.8 x 1.4 x 6.1 x 8.8 x 9.3 x 9.0 x 9.3 x 6.6 x 6.4 x 6.6 x 1.1 x 1.0 x 1.1 x
1-Hexen-6-01.
2 . 4 X lo-?
