Diterpenes, bioactive synthesis

ABSTRACT This article reviews the literature published dealing with the synthesis of some bioactive diterpenes. It describes the biological activity and synthesis of only four diterpenes pisiferic acid, camosic acid, triptolide and miltirone. This review excludes the discussions of Taxodione, a bioactive diterpene, because it has already been reviewed [85], The utility of several reagents in the total synthesis of terpenoid compounds has been documented. It can be observed that several routes have been developed for the synthesis of a single diterpene. 

This review aims to present the most relevant aspects of the synthesis of the above mentioned bioactive diterpenes. It also describes the preparation of several potential intermediates, which have been utilized for the total synthesis of these bioactive diterpenes. 

Various other synthetic studies on bioactive quassinoids have been described in the literature [122-124], such as synthesis of a picrasane-related intermediate from diterpenes constituents from Cupresaceae species, such as Juniperus communis [125],... 

ABSTRACT The Wieland-Miescher ketone (1) and its methyl analog (2) have been utilized for the synthesis of several sesquiterpenes like warburganal, muzigadial, albicanol, etc. Similarly several bioactive diterpenes like taxodione, pisiferic acid, aphidicolin, etc., have been synthesized from these ketones. The utility of several reagents in the total synthesis of terpenoid compounds has been documented. The developments of several routes for a single terpene from these ketones have been discussed. 

The above review indicates that Weiland-Miescher ketone and its methyl analog can serve as versatile and valuable starting materials for a variety of bioactive diterpenes and sesquiterpenes. It has been also utilized for the synthesis of a number of terpenoid and steroidal compounds whose discussions have been omitted in this review. A number of novel reactions have been realized and used to advantage in pursuing the culmination of the synthesis of several natural products. These two ketones have been utilized in the synthesis of various intermediates with the desired stereochemistry. We believe that in the near future the utility of these two ketones can be observed in the synthesis of products useful for agrochemicals, perfume and pharmaceutical industries. 

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