(+) 2-butanol has specific rotation of + 13.9° when measured in pure form. A sample of 2-butanol was found to have an optical rotation of –3°. What is the stereomeric composition of this mixture ?
Let x is the % of (+) 2-butanol.
13.9 x – 13.9 (100 – x) = – 300.
x = 39.2, % of d form = 39.2, % of l form = 60.8.