[omoli062]

I have a little problem with this reaction, a have to do the synthesis of  a pyrane from a lactone , All R most be only alkyl groups any idea???

[AWK]

This is a problem, how to form C-C bond from oxygen function

[Winga]

I have a little problem with this reaction, a have to do the synthesis of  a pyrane from a lactone , All R most be only alkyl groups any idea???

I think the 1st step is to eliminate all the -OH groups, and the major product should be conjugated one.
Then, additions of alkyl groups, e.g. 1,4 addition (not quite sure).
About the C=O group, use ylide to convert to C=CRR'.

[AWK]

About the C=O group, use ylide to convert to C=CRR'.

Does lactone carbonyl group react with ylide?

[Winga]

About the C=O group, use ylide to convert to C=CRR'.

Does lactone carbonyl group react with ylide?

Not sure!

[movies]

About the C=O group, use ylide to convert to C=CRR'.

Does lactone carbonyl group react with ylide?

If by ylide you are referring to a Wittig reagent, then no, it won't react with an ester/lactone.

There are other reagents to convert an ester/lactone to an enol ether though, including the Tebbe reagent and the Petasis reagent.