Science of Synthesis

Braun, M., Science of Synthesis, (2007) 35, 333.

The reaction of alcohols with triphenylphosphine and carbon tetrabromide is a mild and efficient method for the preparation of primary and secondary alkyl bromides ‌15‌. Primary hydroxy groups have been shown to react selectively in the presence of secondary ones. The method has been used frequently in carbohydrate and nucleoside-type substrates as well as with sensitive substrates containing allenyl moieties. It leads to complete inversion at stereogenic hydroxy-bearing carbon atoms. Illustrative examples are shown in ‌Scheme 15‌.

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‌Meeeeeeeeee 88‌

M8	Meeeeee	Meeee (%)	Mee
(MM8)8MM=M=MM(MM8)8Me	MM8Me8	88	[‌88‌]
(MM8)8MM=MM8	MM8Me8	88	[‌88‌]
(M,M)-(MM8)8MM=MMMM8MM=MM(MM8)8Me	MM8Me8	88	[‌88‌]
	eeeeeeee	88	[‌88‌]
MMMe(MM8)8MM=MMe8	MM8Me8	88e	[‌88‌]
MM8MMe8MM8MM=MM8	MeMM	88	[‌88‌]
	MMM	88	[‌88‌]

e (M)-8-Meeeeeeeee-8-ee-8-ee (>88% ee) eeeee (M)-8-eeeee-8-eeeeeeeeee-8-eee (>88% ee).

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‌Meeeeeeeeee 88‌

e Meeeeeeee-8β-ee eeeee 8α-eeeeeeeeeeeeeee.

Meeeeeeeeeee Meeeeeeee

8-Meeeeeeeeeee-8,8-eeeee [‌88‌, (MM8)8MM=M=MM(MM8)8Me]; Meeeeee Meeeeeeee:[‌88‌]

Me e eeeeeeeeeeee eeeeeee eeee ee eeeeeee-8,8-eeee-8-ee (8.88 e, 88.8 eeee) eee MMe8 (8.88 e, 88.8 eeee) ee MM8Me8 (88 eM) eee eeeee, ee eeeeeeee eeee eee-eeee eeeeeee, Me8M (8.88 e, 88 eeee). Meeee eee eeeeeeee eee eeeeeeee, eee eeeeeee eee eeeeeee eee ee eeeeeeeeee 8 eee, eeeeeeeee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Me8M (88 eM) eee eeeee eee eee eeeeeee eee eeeeeeee. Mee eeeeee eeee eee eeeeee eeee Me8M (8 × 88 eM). Mee eeeeeeee eeeeeeee eee eeeeeeee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee Meeeeeeee eeeeeeeee ee eeee 8-eeeeeeeeeeee-8,8-eeeee ee e eeeeee eeeeeeeee eee; eeeee: 8.88 e (88%); ee 88°M (eeee)/88 Me.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88e8, 888.