[Dynamo22]

I'm not looking for the answer straight out, I just wanted some help. I've always had trouble remembering the ring opening reagents, mechanisms, etc. Any tips on how to start to solve this one?

Edit*: The available reagents in the drop boxes are: H2/Pt, O3 then Zn/H2O, CH3MgBr then H3O+, O3 then H2O2, H3PO4 and heat, and CH3CO3H then H2O.

[sjb]

Can you work backwards, perhaps? How can you make the keto ester?

[orgopete]

Hint, I think reagent 3 is the O3 then H2O2.

[zhangcarlin]

Hint, I think reagent 3 is the O3 then H2O2.

And then CH3CO3H then H2O

[orgopete]

Hint, I think reagent 3 is the O3 then H2O2.

And then CH3CO3H then H2O

Why?

[zhangcarlin]

Hint, I think reagent 3 is the O3 then H2O2.

And then CH3CO3H then H2O

Why?

Oxidation the aldehyde to carboxylic acid

[orgopete]

There were two different ozonization procedures, one with a reductive work up and one with an oxidative work up. I suggested the oxidative work up. An oxidative work up converts aldehydes to acids.

[Dynamo22]

Hey guys, sorry for taking so long to get back to you, holidays got a hold of me. Thanks for the hints, I got it figured out. Did the Grignard, reduced the 2° alcohol to alkene, then used the CH3CO3H to get the resultant product. Checked out just fine.