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DOI: 10.1055/sos-SD-043-00383

Sankararaman, S.Science of Synthesis, (200843442.

The conversion of an aldehyde by chain extension into an alkyne via the formation of a 1,1-dibromovinyl derivative is known as the CoreyFuchs reaction[‌24‌] {Scheme 11; see also Science of Synthesis, Vol.27 [Heteroatom Analogues of Aldehydes and Ketones (Section]}. The aldehyde is converted into the corresponding 1,1-dibromo derivative by reaction with carbon tetrabromide and triphenylphosphine, either with or without zinc. The dibromovinyl derivative is treated with a strong base, such as butyllithium or lithium diisopropylamide, to yield the alkyne. The intermediate acetylide can be protonated (e.g., to give 19), or either silylated or alkylated by quenching the reaction with an alkyl bromide or chlorotrimethylsilane (e.g., to give 20) prior to workup.

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Meeeee 88 MeeeeMeeee Meeeeeeee ee e Meeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Mee-8-eee [88, M8=(MM8)8Me]; Meeeeee Meeeeeeee:[‌88‌]

8,8-Meeeeeeeee-8-eee (8.888e, 8eeee) ee MMM ee 88°M eee eeeeeee eeee 8.88M MeMe ee eeeeeee (8.8eM, 8.8eeee). Meeee eeeeeeee ee 88°M eee 8e, eee eeeeeee eee eeeeeee ee eeee ee 88°M eee eeeeeeeeee ee eeee eeeeeeeeeee eee 8e. Meeeeee eeeeee eee eeeeeee eeeeeeeeee, eeeeeeee ee eeeeeeeeeeee, eeee eee-8-eee; eeeee: 8.88e (88%).

8,8-Mee[(eeeeeeeeeeeeee)eeeeeee]eeeeee (88); Meeeeee Meeeeeeee:[‌88‌]

Me 8,8-eee(8,8-eeeeeeeeeeee)eeeeee (8.8e, 8.8eeee) ee MMM ee 88°M eee eeeee 8.8M MeMe ee eeeeee (8.8eM, 8.8eeee) eee eee eeeeeee eee eeeeeee ee 88°M eee 8e. Me eee eeeeeeee eeee MMMMe (8.8eM, 8.8eeee) eee eeeeeee ee 88 ee 88°M eee 88eee, eee eeee 8M MMe (88eM) eee eeeee. Meeee eeeeeeee eeeeeee eeeeee eee eeeeeeeeee eeee eeeeeee, eeeeeeee ee eeeeee eeeeeeeeeeeeeee eeeeeeeeeeee, eee eeeeeee eee eeeeeeee ee eeeeeeeee eeeeeeee; eeeee: 88ee (88%).

8,8,8-Meee[(8-eeee-eeeee-8,8-eeeeeeeeeeeeeee)eeeeeee]eeeeeee (88); Meeeeee Meeeeeeee:[‌88‌]

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