Prepd from 1-pentanol and concd HCl in sealed tube at 120°: Conant, Kirner, J. Am. Chem. Soc. 46, 245 (1924); with HCl and zinc chloride: Clark, Streight, Trans. R. Soc. Can. Sect. 3 23, III 77 (1929); Vogel, J. Chem. Soc. 1943, 638, 640; for prepn without admixed 2- and 3-chloropentanes see Whitmore's procedure from 1-pentanol with SOCl2 and pyridine: Whitmore et al., J. Am. Chem. Soc. 60, 2540 (1938); Mixer, Young, ibid. 78, 3382 (1956).