TBSOTf-assisted three component coupling of epoxides, THF, and ylides derived from the phosphoniosilylation products of enones and α,β-unsaturated lactones

Ylides 3, derived from the phosphoniosilylation products of enones and α,β-unsaturated lactones, were reacted with epoxides 4 and TBSOTf in THF. Interestingly, the three component coupling products 5-8 were obtained after subsequent desilylation.     

Complete NMR spectral assignments of two lactucin-type sesquiterpene lactone glycosides from Picris conyzoides

Complete (1)H and (13)C NMR signal assignments of two lactucin-type sesquiterpene lactone glycosides, derivatives of 11β,13-dihydrolactucin, isolated from roots of Picris conyzoides, were achieved by one- and two-dimensional NMR experiments, allowing the correction of previously published data for cichorioside B and the structure elucidation of its new ester with 3-hydroxy-2-methylpropanoic acid. In addition, seven known sesquiterpene lactones and three phenolic compounds were isolated from the plant material.     

1H and 13C NMR signal assignments of a novel Baeyer-Villiger originated diterpene lactone

A highly rearranged novel dilactone was the single product isolated from Baeyer-Villiger oxidation of a norketone prepared from grandiflorenic acid, a natural kaurane diterpene. The complete 1H and 13C NMR assignment is presented for this novel compound that showed discrete in vitro antibacterial activity.     

A simple and efficient approach to 1,3-polyols: application to the synthesis of cryptocarya diacetate

A highly enantio- and stereoselective synthetic strategy for both syn- and anti-1,3-polyols has been developed. The sequence involves iterative Jacobsen's hydrolytic kinetic resolution (HKR), diastereoselective iodine-induced electrophilic cyclization, and ring-closing metathesis (RCM). This protocol has subsequently been utilized for the synthesis of cryptocarya diacetate, a natural product with broad range of biological activity.