Allylic glycols

Claisen rearrangement of glycolates. Two laboratories 2 have reported that allylic glycolate esters undergo Claisen-Ireland rearrangement (6, 276-277) with useful diastereoselectivity. This rearrangement was used in a synthesis of 1, the aggregation pheromone of the European elm bark beetle.1... 

A Special feature of the boron or tin triflate mediated Claisen rearrangement of allylic glycolates or related substrates is that they avoid strongly basic conditions and thus eliminate the need to generate silyl ketene acetal intermediates in which C-silylation is a potential problem497. 

A novel synthesis of (+)-avenaciolide (341) centres on the stereospecific elaboration of the anti-ester (339) by an enolate Claisen rearrangement of the corresponding ( Z)-allylic glycolate and a highly stereoselective selenolactonization of the derived... 

Diallyl iso- Diallyl chloren- Diallyl Diallyl Tri allyl glycol bis-... 

In 1983, Burke et al. reported the enoHzation of an allylic glycolate in the presence of the unprotected cyclopentenone (Scheme 4.45) [48]. Only sHghdy over one equivalent of base was necessary to effect the enolization at -100 °C, indicating that concomitant enohzation of the enone was not competitive. The stereochemical outcome of the rearrangement of the Z-silyl ketene acetal is consistent with the expected chair-like transition state. 

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