78168-26-0

Upstream product

• 34745-78-3 cyclohex-2-en-1-yl propionate 
• 18162-48-6 tert-butyldimethylsilyl chloride 
• 822-67-3 Cyclohex-2-enol 
• 115-80-0 Triethyl orthopropionate 
• 78709-96-3 tert-Butyl-[(Z)-1-(cyclohex-2-enyloxy)-propenyloxy]-dimethyl-silane 

Relevant academic research and scientific papers

Stereochemical Control in the Ester Enolate Claisen Rearrangement. 2. Chairlike vs Boatlike Transition-State Selection

The preference for chair-and boatlike transition-state geometries in the ester enolate Claisen rearrangement of straight chain, carbocyclic, and heterocyclic propanoates was investigated.A novel stereoelectronic effect in pyranoid and furanoid glycal systems leads to a significant relative stabilisation of the boatlike vs the chairlike TS(excit.).The preferred transition state in six- and five-membered carbocyclic systems is highly dependent on steric factors, as the energy difference between chair-and boatlike TS(excit.) tends to be small.With straight-chain substrates, a significant contribution of the boatlike TS(excit.) to the rearrangement product mixture is only expected in bis-donor substituted allylic esters.

Evaluation of the Claisen Rearrangement of 2-Cyclohexenols for the Stereoselective Construction of a Terpene Synthon

A variety of stereocontrolled propanoate Claisen rearrangement procedures was applied to 2-cyclohexenol and the trans-6-methyl-substituted derivative.The ester-enolate procedure afforded the RS,SR diastereomers 6a and 8a predominantly, regardless of enolate geometry, indicating a preference for the boatlike conformation in rearrangement of the ketene acetals in which the methyl and cyclohexenyloxy groups are trans.Similar boat specificity is seen on rearrangement of (E)-ketene N,O-acetals.A model is proposed to explain the alternating chair-boat specificity.Evaluation of these reactions with cis-6-methyl-2-cyclohexenol was foiled by poor yields of rearranged products.An alternative, highly stereoselective route to both diastereomers of p-menth-1-en-9-ol was developed by using kinetically controlled alkylation and epimerization of a bicyclic lactone intermediate to control the stereochemistry.