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35.2.5.2.2 Method 2: Hydrobromination of Epoxides Using Elemental Bromine

DOI: 10.1055/sos-SD-035-00442

Rück-Braun, K.; Freysoldt, T.Science of Synthesis, (200735505.

The ring opening of epoxides 8 using bromine is not possible without an additive. Most of these reagents are simply precursors for the in situ generation of hydrogen bromide, which is formed via bromination of the additive (Scheme 6).[‌8‌‌11‌] These tandem reactions are nevertheless efficient tools for the formation of β-bromo alcohols 9 and 10, but require the use of elemental bromine, which should be avoided if possible because it is a highly toxic reagent. Furthermore, these reactions are inefficient in terms of atom economy because about 50% of the bromine is lost. In addition, there are environmental problems due to the disposal of very acidic byproducts. These are disadvantages of bromine compared to the direct use of hydrogen bromide.

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Meeee 8 Meeeeeeee ee β-Meeee Meeeeeee ee Meee Meeeeee ee Meeeeeee Meeee Meeeeee[‌8‌,‌88‌‌88‌]

M8 M8 M8 Meeeeeeee Meee (°M) Meeee (88/88) Meeee (%) Mee
M M M M 8888 88 [‌8‌]
Me M M M 8888 88:88 88 [‌8‌]
MM8Me M M M, M, M, M, M, M ee 88 eeee 8888 [‌88‌,‌88‌‌88‌]
Me M M M, M, M, M, M, M, M, M, M, M, M ee 88 eeee 8888 [‌88‌‌88‌]
MM8MMe M M M, M, M, M, M, M, M, M, M, M ee 88 eeee 8888 [‌88‌‌88‌]
M MM8MM MM8MM=MM (MM8)8MMe M 8 8:88 88 [‌88‌]
(MM8)8 M M, M, M, M, M, M, M, M, M ee 8888 [‌88‌‌88‌,‌88‌‌88‌]
MM(MM)(MM8)8 M M 8 88 eeee 88 [‌88‌]

e M: eeeeeee; M: eeeeeeeeeeeeeee; M: eeeeeee-8,8-eeeeeee; M: eeeeeeee; M: eeeeeee eeeeeee; M: eeeeeeeeeeee eeeeeeeee; M: eeeeeeee-eeeeeeeeee eeeeeeeeeee; M: Meeeee eeee eeeeeeeee; M: eeeee eeeeee; M: eeeeeeeeeeeeeeeee; M: 8,8-[(8-eeeee-8-eeeeeee-8,8-eeeeeeeee)eee(eeeeeeeeeeee)]eeeeeeeee; M: 8-(8-eeeeeeeeeeeeeeeeee-8-ee)eeeeeeee; M: Me(MeMe)8.

Meeeeeeeeeee Meeeeeeee

8-Meeee-8-eeeeeeeeeeeee (88, M8=Me; M8=M8=M); Meeeeee Meeeeeeee Meeee Meeeeeeeeeeeeee:[‌88‌]

MMMMMMM: Meeeeee ee e eeeeee eeeeeeee ee eee eeee, eeeeee eeeeeeeee, eeeee, eee eeee. Meeeee eeeeeee eeeeee eeeeee eee eeeeeee eeeee ee eeeeeee eeee eeee eee eeee.

Meeeeeeeeeeee (88, M8=Me; M8=M8=M; 888ee, 8eeee) eee eeeeeeeee ee MM8Me8 (8eM) eee eeeee ee e eeee ee eeeeeeeeeeeeeee (88.8ee, 8.8eeee) ee MM8Me8 (8eM). Me8 (8eeee) ee MM8Me8 (8eM) eee eeeee ee eeeeeeee eeee 88eee. Meeee 8e, eee eeeeeeee eee eeeeeeee (ee eeeeeeeeee ee MMM eee MMM) eee eee eeee eee eeeeee eeee 88% ee Me8M8M8 (8×88eM) eee M8M (8×88eM). Mee eeeeeee eeeee eee eeeee (MeMM8) eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee); eeeee: 888ee (88%); ee 888888°M/8.8Meee.

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