A concise asymmetric total synthesis of the sex pheromone of the tea tussock moth has been achieved from commercially available starting materials. The chiral moiety was introduced by Evans’ template and the key CC bond construction was accomplished through Julia-Kocienski coupling and Wittig olefination. The salient characteristic of our synthetic route is that it is protecting a group free.Download high-res image (127KB)Download full-size image

According to our retrosynthesis, the main chain of the target molecule could be constructed using a C5 + C7 + C5 strategy. The key induction reaction afforded chiral methyl group moieties using different Evans templates with different configurations. Li2CuCl4 was effectively employed in the Csp3Csp3 coupling protocol. The target molecular was obtained in a 12.6% overall yield with nine steps in the longest linear route.Download high-res image (74KB)Download full-size imageThe synthesis of the Paulownia bagworm sex pheromone has been achieved through a C5 + C7 + C5 strategy, using Evans induction and Csp3Csp3 bond construction.

An efficient approach for asymmetric synthesis of (+)-spicigerine, (+)-cassine and their 3-epimers has been developed through the intramolecular diastereoselective tandem addition/cyclisation process of α-chiral aldimine 9 with methylmagnesium bromide and the asymmetric addition of nucleophilic reagents to aminal 14. Moreover, the first asymmetric synthesis of (+)-spicigerine has been achieved in this manuscript. In this synthetic strategy, the asymmetric syntheses of (+)-spicigerine and (+)-cassine was achieved in a 14% overall yield and nine steps and an 18% overall yield and seven steps from cheap α-chiral aldimine 9, respectively.

The one-pot tandem process of (2R,4R,SRS)-15 with Grignard reagents for highly diastereoselective synthesis of functionalized 2-piperidinone 1 was developed. Furthermore, the divergent syntheses of L-685,458 3 and its six analogues 20a–f have been conveniently achieved using this effective protocol as the key step.

A highly efficient palladium-catalysed phenyl diazonium tetrafluoroborate participation of C–H activation ring closure protocol has been developed. A series of 6H-benzo[c]chromenes have been synthesized by intramolecular cyclization of ortho diazonium salts tetrafluoroborate of benzyloxyphenyl (Method A), or phenoxymethyl phenyl (Method B). The transformation allows the synthesis of 6H-benzo[c]chromenes with a wide variety of functional groups and substitution patterns from simple and easily accessible precursors.

Several bisabolane sesquiterpenes, (±)-curcumene, (±)-curcuphenol, (±)-curcudiol and (±)-curcuhydroquinone, have been synthesized in racemic form and fully characterized. The salient characteristic of our approach is that a Johnson-Claisen arrangement was involved as a key step.