Rhodium carbenoid mediated cyclizations. Part 4. Synthetic approaches to oxepanes related to zoapatanol was written by Davies, Martin J.;Heslin, Julie C.;Moody, Christopher J.. And the article was included in Journal of the Chemical Society in 1989.Quality Control of (2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate The following contents are mentioned in the article:
Synthetic approaches to the oxepane diterpene zoapatanol (I) are described in which the key step is the formation of the 7-membered cyclic ether by a Rh carbenoid cyclization. The approaches to the functionalized side chain of I centered on allylic alcs., (E)RCMe:CHCH2OH [R = CH2CH2CH2CHMeCHO, CH2CH2CH:CMeCH2OH-(E)], prepared from geraniol. After asym. epoxidation, these substrates were converted to diazo alcs. II. Finally, cyclization with Rh(OAc)2 gave oxepanes III which were characterized as silyl enol ethers IV. This study involved multiple reactions and reactants, such as (2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate (cas: 37905-02-5Quality Control of (2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate).
(2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate (cas: 37905-02-5) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Quality Control of (2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics