Effects of Substituents on Alkanes

The OH substituent is attached internally (rather than terminally ) to the linear alkane chain of pentane the point of attachment is labeled a, which corresponds to 03 of pentane, for which the shift value of 34.7 is given in Table 5.3. To this value is added the increment + 41, this being the increment for an OH group attached internally to the a carbon of 3-pentanol (see line 12,2nd column of numbers). The shift, therefore, for the point of attachment (the a carbon) is calculated as 75.8. The 0 and y shifts are calculated as follows. All of the calculated shifts are in reasonable agreement with the determined values (Table 5.11). 

1-Pentanol would be treated similarly but as a terminal alcohol, and the carbon atom to which the OH group is attached would again be labeled a. 

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