Study of the solvolysis of derivatives of menthol [5-methyl 2 (I methylethyl) cyclohexanol] has greatly enhanced our understanding of these types of reactions. Heating the isomer of the 4-methylbenzenesulfonate ester shown below in 2, 2, 2-trifluoro-ethanol (a highly ionizing solvent of low nucleophilicity) leads to two products with the molecular formula C10H18.
(a) The major product displays 10 different signals in its l3C NMR spectrum. Two of them are at relatively low field, about ( ~ 120 and 145 ppm, respectively, The 1H NMR spectrum exhibits a multiplet near 5 = 5 ppm (1 H); all other signals are upheld of ( = 3 ppm. Identify this compound.
(b) The minor product gives only seven l3C signals. Again, two are at low field (8 ~ 125 and 140 ppm), but, in contrast with the 1H NMR data on the major isomer, there are no signals at lower field than ( = 3 ppm. Identify this product and explain its formation mechanistically.
(c) When the solvolysis is carried out starting with the ester labeled with deuterium at C2, the 'H spectrum of the resulting major product isomer in (a) reveals a significant reduction of the intensity of the signal at 8 = 5 ppm, a result indicating the partial incorporation of deuterium at the position associated with this peak. How might this result be explained?