# How to I identify the diene and dienophile through retrosynthesis of a given compound?

I'm stuck while finding what to use to make this compound:

My first attempt was to use a triple bond as dienophile and a ring as my diene, as shown below -

But I'm not sure if this is right.

• Welcome to chemistry.se! This appears to be a homework question, please share your thoughts and attempts towards the solution. For formatting help visit the help center and for more information about this page, take the tour. Also your product lacks some charges or protons. – Martin - マーチン Feb 26 '15 at 7:41
• Thats the way it was given to me by a friend but yeah there would be a -2 on the co3 It would be trivial if the bottom double bond was on the bond that connects the two rings but using the diels-alder mechanism I can't really see how to get that structure. Why guess so far is I need a triple bond dieophile and a ring as my diene – Loststudent22 Feb 26 '15 at 7:45
• It would be great if you could would your retrosynthesis (the one from your comment) into your question! It would be a waste if the question would get closed despite the fact that you have definitely thought on it and came to a reasonable approach! – Klaus-Dieter Warzecha Feb 26 '15 at 8:57
• The compound as drawn is impossible. You're alluding to carbonate [CO3(2-)] in the comment, but that cannot be attached to the structure. Draw it out completely to convince yourself. One mistake in a structure makes me skeptical about the accuracy of the rest. – jerepierre Feb 26 '15 at 15:03

## 1 Answer

The $\ce{CO3}$ substituents are questionable. Let's assume that this is $\ce{CO2Me}$ instead!

Since this is homework, I won't provide a full solution but:

1. Note that double bond patterns may isomerize (in the direction of conjugation).
2. Alkynes can serve as dienophiles too!

• !Diels-Alder product This was my first attempt is this on the right track? Not quite right yet. – Loststudent22 Feb 26 '15 at 8:18
• @Loststudent22 Diels-Alder reaction looks fine to me. Remember #1 in my answer. What about adding a strong, bulky base and subsequent quenching? – Klaus-Dieter Warzecha Feb 26 '15 at 8:34
• I kind of see what your saying, so the reaction couldn't be done in one concerted mechanism? – Loststudent22 Feb 26 '15 at 8:49
• @Loststudent22 I just don't see that, but maybe I'm missing something and I'm preoccupied with the same retrosynthesis that you had in mind too. – Klaus-Dieter Warzecha Feb 26 '15 at 8:52