The mixed pinacol coupling reaction has been carefully analyzed. Although a trend toward statistical distribution of products can be found, it is observed that true statistical distributions are rarely observed. Ring-size and alkyl substituent effecta are examined. A through-space heteroatom influence on coupling is noted. By use of (R)-(+)-3-methylcyclohexanone, a very specific effect of coupling conditions on product stereochemistry is observed.
![[1,1'-Bicyclohexyl]-1,1'-diol Structure](https://image.chemsrc.com/caspic/295/2888-11-1.png)