2-methylcyclohexyl tosylate

Base-promoted E2 elimination involves simultaneous loss of and X from neighboring carbons. Applying this rule to 2-methylcyclohexyl tosylate suggests that two different products might form, but the actual situation is more complicated. One tosylate isomer gives only one of the two possible alkenes, while the other gives both. 

Examine all of the low-energy (within. 004 au or 3 kcal/ mol of the lowest-energy conformer) conformers of cis-2-methylcyclohexyl tosylate. Identify every conformer that can undergo anti elimination of OTs and H+, and predict the alkene that will be produced. What alkenes will be obtained from the cis tosylate ... 

Analyze the low-energy conformers of trans-2-methylcyclohexyl tosylate in the same way. What alkenes will be obtained from the trans tosylate ... 

The stereoelectronic requirements of groups undergoing base-promoted elimination is also easily seen by stereochemical studies. Treatment of trans-2-methylcyclohexyl tosylate gives 3-methylcyclohexene as the major product while treatment of czs-2-methylcyclohexyl tosylate gives the more stable 1-methylcyclohexene as tire only product. 

---