A new diterpenoid acetate from Sideritis reverchonii

Sideritis spp.: Uses, chemical composition and pharmacological activities—A review

“…Diterpenoids analysis have revealed that the species occurring in the Eastern and Central Mediterranean area (Turkey, Greece and Italy) contain almost exclusively kaurane diterpenes (Topç u et al, 1999(Topç u et al, , 2002aFraga et al, 2003a,b;Kilic et al, 2003;Kilic, 2006), whereas species growing in Western Mediterranean area and Macaronesic regions present diterpenes with different carbon skeleta (ent-kaurene, labdane, atisene, pimarane, beyerane, trachilobane and rosane) (de Quesada et al, 1974;Márquez et al, 1975;García-Granados et al, 1982;Cabrera et al, 1983). Kaurene diterpenes derivatives (foliol (5), sidol, linearol, sideridiol and isolinearol) are the most frequently found in Sideritis species.…”

Synthesis of sesquiterpenoids of the drimane group from labdane diterpenoids

“…It should be noted that norambreinolide 7 was prepared by the cleavage of not only sclareol 4 but also other labdane diterpenoids: ct-and 13-1evantenolide (19 and 20, respectively), 16 manoyl oxide (21), [17][18][19] 12ct-hydroxy-13-epimanoyl oxide (22), z~ cis-abienol (23a), 9,21-z3 trans-abienol (23b), 9,z4,25 stereoisomeric 8,12-epoxylabd-14-en-13-ols (24),26 borjatriol (25)Y labdane-Sct,15-diol (26), z8.29 and labdanolic acid (27). Ozonization of sclareol 4 in methanol and treatment of the ozonization product with ammonium chloride yielded compound 17; 15 the latter is quantitatively converted into 13-diketone 18 upon ozonization.…”

“…In fact, whereas some labdanoids such as sclareol 4, manool 5, neoabienols 6a, b, and manoyl oxide 21 can be converted into drimane compounds in two to four steps using accessible and cheap reagents, the preparation of drimanes from labdanolic (27), zamoranic (100), and communic (141a) acids and hispanoione 72 requires multistep procedures associated with the use of expensive reagents or reagents difficult to access; therefore, the practical value of these methods still remains problematic. At present, the labdanoids mentioned above are not equally suitable as initial compounds for the synthesis of drimanes.…”