13901-85-4Relevant articles and documents
SEVERAL NEW CEMBRANOID DITERPENES FROM THREE SOFT CORALS OF THE RED SEA
Kinamoni, Zvia,Groweiss, Amiram,Carmely, Shmuel,Kashman, Yoel,Loya, Yossi
, p. 1643 - 1648 (1983)
Eight new diterpenoids have been isolated from three soft corals, Alcyonium utinomii, Lobophytum pauciflorum and Lobophytum crassum.The compounds were shown to be: 1,3,7,10-cembratetraen-12-ol (4); 1,3,6,11-cembratetraen-8-ol (5); 1,3,7,12(20)-cembratetraen-11-ol (6a); 2,7,11-cembratetraen-4,15-diol (8); 3,7,10-cembratrien-12,15-diol (9); and the lobolide related deacetyldeepoxy lobolide (15); deepoxy lobolide (16) and deacetyl-13-hydroxy lobolide (17), by spectral data and chemical studies (mainly ozonolysis).
Biogenesis-Guided Synthesis and Structural Revision of Sarocladione Enabled by Ruthenium-Catalyzed Endoperoxide Fragmentation
Ning, Yuhan,Tian, Hailong,Gui, Jinghan
supporting information, p. 11222 - 11226 (2021/04/19)
Sarocladione is the first 5,10:8,9-diseco-steroid with a 14-membered macrocyclic diketone framework to have been isolated from a natural source. Herein we report a biomimetic synthesis of sarocladione in only two or seven steps from inexpensive, commercially available ergosterol. The key feature of this synthesis was a novel ruthenium-catalyzed endoperoxide fragmentation, which transformed various saturated endoperoxides into olefinic diketones by cleavage of two C?C bonds. This synthesis allowed us to unambiguously determine the structure of sarocladione and provided experimental support for its revised biosynthetic origin. This work also vividly demonstrates that consideration of the biogenesis is a powerful tool for elucidating the structures of natural products.
Ozonolysis of bicyclic 1,2-dioxines: Initial scope and mechanistic insights
Cain, Nicole M.,Tiekink, Edward R. T.,Taylor, Dennis K.
, p. 3808 - 3819 (2012/06/29)
The ozonolysis of bicyclic 1,2-dioxines was investigated using a variety of 1,4-disubstituted 1,2-dioxines along with a 1,3-dialkyl and steroidal example, with yields ranging from moderate to excellent. Two different pathways were observed upon reaction of the 1,4-disubstituted 1,2-dioxines with ozone; one pathway saw the "expected" results, that is, cleavage of the olefinic moiety with generation of 1,4-dicarbonyl 1,2-dioxines, while the other pathway revealed a previously unobserved rearrangement involving cleavage of the peroxide linkage along with loss of either CO or CO2. Several unsymmetrical ozonolyses were also performed to further investigate the origins of this rearrangement, and initial mechanistic insights into the fragmentation pathways are discussed.
Synthesis and chemistry of 2,3-dioxabicyclo[2.2.2]octane-5,6-diols
Valente, Peter,Avery, Thomas D.,Taylor, Dennis K.,Tiekink, Edward R. T.
experimental part, p. 274 - 282 (2009/04/10)
(Chemical Equation Presented) 1,4-Disubstituted 2,3-dioxabicyclo[2.2.2]oct- 5-enes were dihydroxylated with osmium tetroxide to yield diols anti to the peroxide linkage in a highly selective manner. Reduction of the peroxide bond furnished cyclohexane-1,2,3,4-tetraols with toxocarol relative stereochemistry in excellent yield. This new methodology was employed to synthesize the natural product (1S,2R,3S,4R,5R)-2-methyl-5-(propan-2-yl)cyclohexane-1,2,3,4-tetrol (1) in a short sequence from (R)-α-phellandrene. Moreover, during the study of the chemistry of 2,3-dioxabicyclo[2.2.2]octane-5,6-diols a hitherto unknown rearrangement was discovered which has wide applicability for the synthesis of 1,4-dicarbonyls, including optically enriched synthons. A broad range of mechanistic investigations applicable to this rearrangement are also reported.
