2-Bromo-3-methyl-2-butene may be used in the preparation of:2,3,4,5-tetramethyl-2,4-hexadiene2-iodo-3-methyl-2-butenediastereomers of 2-amino-3-hydroxy-4,5-dimethylhexanoic acidlithium reagent, 2-lithio-3-methylbut-2-eneD-allo-(2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid-containing peptide, pipecolidepsin A.