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Synthesis of polyfunctional triterpene derivative [8(27),13E,17E,21E]-15-phenylsulfonyl-16-oxobicyclofarnesylfarnesol benzyl ether (8) from commercially available monoterpene geraniol and diterpene manool has been accomplished in 73% yield and its chemical transformation in superacid medium has been investigated. An unexpected rearrangement of 8 occurred, which involved methyl migration in the bicyclic fragment and total inhibition of the lateral polienic chain. A new bicyclic triterpene product [5(10),13E,17E,21E]-15-phenylsulfonyl- 16-oxo-30(10→9)-abeo-bicyclofarnesylfarnesol benzyl ether (9), with rearranged new carbon skeleton has been obtained. Its bicyclic moiety is analogous to this of a natural triterpene neopolypodatetraene.

A relatively simple method for isolation of the mixture of ent-kaur-16-en-19-oic (1) and ent-trachiloban-19-oic (2) acids from dry waste of sunflower processing has been elaborated, and it has been shown that the waste can serve as an accessible source of ent-kauranic and ent-trachilobanic diterpenoids.

A review of diterpenoid cyclization initiated by electrophilic reagents is provided. Conventional protonic and Lewis acids are examined along with superacids as initiators of cyclization cascade. An emphasis is placed on the use of cyclization reactions as a tool for the synthesis of compounds with potential practical utility. The review contains 74 references.

The known diterpenic ester – 15α-angeloyl-ent-kaur-16-en-19-oic (angeloylgrandifl oric) acid has been isolated from the dry wastes of Helianthus annuus L. The synthesis of 15α-hydroxy- and 15-oxo-ent-kaur-16-en-19- oic acids starting from ent-kaur-16-en-19-oic acid has been performed.