The E and 2-5-deutenoadamant-2-ols have been synthesized by an unambiguous route. The =C NMR spectra show the familiar 1 : 1 : 1 splitting of one of the C-5 or C-7 signals, thus allowing a definite assignment of the &atoms to be made. This assignment is in accord with the conclusion of Duddeck and Islam. Revised assignments are offered for the reported configurations of the 5-bromo-and -chloro-adamantan-2-ols, and several unusual remote deuterium isotope shifts are reported.Substituted adamantanes provide an obviously very useful carbon skeleton on which a variety of stereochemical studies can be based. In our attempts to develop 5-substituted adamantan-2-01s as a new stereochemical probe, we found ourselves hampered by an uncertainty in the assignment of the resonances of the 6-carbon atoms in the parent alcohol 1-OH,H (to minimize confusion, we ignore the point here that lo&y 6 E-or Z-1-X,Y, where X is the 2-substituent and Y the 5-substituent some of the '2,5-disubstituted' derivatives are not properly named. Thus, 1-OH,OH is, correctly, adamantane-l,Cdiol, etc.). The history is as follows. Pekhk et a1.l observed that the two Z-y-carbon atoms (relative to X) are shifted fairly far upfield compared with the E-pair; they made the assignment of these signals by comparing the spectra with those of known borneols, norbornanols and other axially and equatorially substituted cyclohexanes. They were unable to resolve the distant bridgehead carbon signals. Maciel et a1.,2 on observing separate signals for these two carbons, tentatively assigned them on the reasonable assumption that the difference between their resonances would have the same sign as that between the neighboring pairs of secondary carbons. However, subsequent studies reported by Duddeck et al. suggested that the assignments of the two 6-atoms should be reversed; they based their opinion on the effects of lanthanide shift reagents (larger for the Z -a t~m ) ,~" (the same conclusion being reached on the same grounds in Ref. 3b), on relaxation times (longer for the E -a t o m~)~ and on an appraisal of the additivity rule as applied to adamantanes. ' Subsequently (in 1977) 1978. In 1983, when Krishnamurthy et aL8 carried out a study of 13C-13C coupling in adamantanes, they took note of all the previous literature reported and emphasized that the assignment of these two signals was tentative (they were, in fact, correctly listed). In a still more recent paper, Duddeck and Islam' granted that their previous assignment had been speculative, but supported it further with a study of the effect of shift reagents on the epimeric 4-deuterioadamantan-2-01s.We now report the synthesis and 13C NMR characterization of E -and 2-1-OH,D; the result provides unequivocal support for Duddeck and Islam's reassignment. During the synthesis, we encountered the E-and Z-haloalcohols 1-OH,Y (Y = C1 or Br), and found that their configurations were also misassigned in the literature. Thus, Giddings and Hudec had reported'' that sodium borohydride reduction of the 5-haloadamantan-2-...