The alcohol shown is treated with phosphorus oxychloride in pyridine, which converts the OH group into a good leaving group for a concerted E2 step with no carbocation. Which structure is the major product?

The alcohol is 3,3-dimethylbutan-2-ol. In acid it would form a cation and rearrange by a methyl shift to the tetrasubstituted 2,3-dimethylbut-2-ene. With POCl3/pyridine the leaving group departs in an E2 step, so no rearrangement occurs and the only beta-hydrogens (on C-1) give 3,3-dimethylbut-1-ene.