Stereoselective Syntheses of cis- and trans-Hexahydrocyclopenta[c]pyran-3(1H)-ones
摘要:
A new access to cis- and trans-hexahydrocyclopenta[c]pyran-3(1H)-ones (1 and 2) has been accomplished stereoselectively through 4-step and 5-step routes, respectively, starting from 2-(hydroxymethyl)cyclopentanone (3).
Expeditious and efficient annulation protocol for the synthesis of α,β-unsaturated δ-lactones from β-keto esters
作者:A. Nangia、P. Bheema Rao
DOI:10.1016/s0040-4039(00)74216-x
日期:1992.4
β-Keto esters 6a–3 are transformed into β-keto alcohols 7a–3, which are homologated to phosphonates 9a–e. Intramolecular Horner-Wadsworth-Emmons reaction affords δlactones 10a–d in excellent overall yields.
Facile synthesis of unsaturated lactones via intramolecular Wittig reaction
作者:Pradeep Kumar、K. Saravanan
DOI:10.1016/s0040-4020(97)10428-8
日期:1998.3
The phosphoranes 3 formed from the reaction of a variety of keto alcohols 1 and (triphenylphosphoranylidene)ethenone 2 undergo intramolecular Wittig cyclization to afford the unsaturated lactones in moderate yields.
Compositions containing certain bicyclic lactones and having insect repellent properties are disclosed. Such compositions comprise a compound of the formula:
or the corresponding unsaturated compound thereof having the formula:
wherein R, R', R" and R''' each are lower alkyl or hydrogen; wherein y is an integer from 1-3, and x and z each are 0 or 1, with the proviso that y is 1 or 2 when x is 1; and a carrier. A method of using such a repellent composition to repel an insect from a situs comprises applying to such situs an effective amount of the composition, with or without the carrier, and thereby repelling the insect from the situs.