Addition of hydrogen halides to alkylidenecyclopropanes: a highly efficient and stereoselective method for the preparation of homoallylic halides

✍ Scribed by Amal I Siriwardana; Itaru Nakamura; Yoshinori Yamamoto

• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 152 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(02)02722-3

✦ Synopsis

The reaction of alkylidenecyclopropanes with HCl or with HBr proceeds very smoothly at 120°C to produce the corresponding homoallylic halides stereoselectively in good to excellent yields. For example, the reaction of (1-phenylbenzylidene)cyclopropane, (1-butylpentylidene)cyclopropane and octylidenecyclopropane with hydrochloric acid produced the corresponding homoallylic chlorides, 4-chloro-1,1-diphenyl-1-butene, 4-butyl-1-chloro-3-octene and (E)-1-chloro-3-undecene in 99, 96, and 87% yields, respectively. The reaction of (1-butylpentylidene)cyclopropane with hydrobromic acid yielded 1-bromo-4-butyl-3octene in 95% yield.