Publication

Cis selectivity of salt-free Wittig reactions: a "Leeward Approach" of the aldehyde at the origin?

Manfred Schlosser
1982
Journal Articles

Abstract

In THF at 25 Deg, Et3P:CHMe reacts with heptanal, Me3CCHO, PhCHO and p-ClC6H4CHO to afford, after 2-4 h, the corresponding olefins in 89-99% yield. In each case the trans isomer prevails, cis/trans ratios ranging from 33:67 to 4:96. The remarkable cis-stereoselectivity of Wittig reactions using triphenylphosphonium alkylides is now attributed to a very specific and almost rigid orientation of the Ph groups around the P atom, which sterically hinders approach to the aldehyde in a way that would lead to the formation of a trans-substituted oxaphosphetane. [on SciFinder (R)]

Official source

https://infoscience.epfl.ch/entities/publication/6da859fd-ec78-48d0-9d9d-32e53b16f7c8

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Manfred Schlosser
1982
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/6da859fd-ec78-48d0-9d9d-32e53b16f7c8

About this result

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Cis selectivity of salt-free Wittig reactions: a "Leeward Approach" of the aldehyde at the origin?

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