The major products M and N in the following reaction sequence are (M) (N) + + LiI · ABC26OR0656
Subject: Organic Chemistry · Chapter: Reagents, Reaction Mechanisms & Named Reactions · Topic: Reagents, Reaction Mechanisms & Named Reactions – General · Exam: GATE 2000-2022 · Marks: 2 · Difficulty: Medium
The major products M and N in the following reaction sequence are 
(M) 
(N) + 
+ LiI
(M) (N) + + LiI(a)M N =
(b)M =
(c)M =
(d)M =
Answer
Answer: A ✓ checked by 4AB · confidence medium
Explanation
LiPPh₂ opens the epoxide by S_N2 at the less hindered carbon (M); MeI forms the phosphonium and the betaine collapses through an oxaphosphetane (syn elimination, Vedejs) so the alkene has the geometry opposite to the epoxide: the two methyls cis, CH₂OMe trans to CH₃ (a).
Study loop for Reagents, Reaction Mechanisms & Named Reactions