Why Do Vicinal and Geminal Dihaloalkanes Undergo Elimination to Afford Alkynes Rather Than Allenes
XU Jia-Xi1**, YANG Zhan-Hui1, MA Yuan2
1. College of Chemistry,Beijing University of Chemical Technology,Beijing 100029,China; 2. Department of Chemistry,Tsinghua University,Beijing 100084,China
Abstract Chain and large cyclic vicinal and geminal dihaloalkanes generally undergo elimination to afford alkynes rather than allenes under basic conditions.Starting from the acidity of hydrocarbons and analyzing hyperconjugations between σC—H and σ<sup>*<sub>C—X,and reactive conformations,the selectivity of vicinal and geminal dihaloalkanes and dihalocycloalkanes in their basic elimination are rationally explained as that vicinal and geminal dihaloalkanes generate the corresponding alkynes rather than allene products under basic conditions.
XU Jia-Xi, YANG Zhan-Hui, MA Yuan. Why Do Vicinal and Geminal Dihaloalkanes Undergo Elimination to Afford Alkynes Rather Than Allenes[J]. Chinese Journal of Chemical Education, 2025, 46(2): 123-125.