試題詳解

22. Which of the following is true about the Witting reaction?
(A) The formation of carbon-carbon double bond from carbonyl compounds (aldehydes and ketones) and triphenylphosphite is known as the Witting reaction.
(B) The Horner-Wadsworth-Emmons reaction is a variation of the Witting reaction. The major is usually the (Z)-alkene isomer.
(C) The Horner-Wadsworth-Emmons reaction involves use of a phosphonate ester instead of a triphenylphosphonium salt.
(D) A cis oxaphosphetane intermediate is formed to produce a ( E )-alkene in the Wittig reaction.
(E) All of these choices.