Bicyclo pentadecan

Intramolecular alkylation reactions employing allylsilanes have been developed. A taxoid bicyclo[9.3. l]pentadecane ring system was prepared via intramolecular alkylation of (150). It is interesting to note that the alkylation occurred in the y-position relative to the alkyne (Scheme 218). A Nicholas reaction was used in the synthesis of (+)-epoxydictymene (Scheme 219). 

The remaining new approaches to muscone all rely upon methods of ring expansion. Ferric chloride treatment of l,4-bis(trimethylsilyloxy)-bicyclo[12,l 0]pentadecane (155), obtained by cyclopropanation of the cyclotetradecene (154) with diethylzinc and methylene iodide, resulted in a one-carbon ring expansion to a muscone precursor, the dione (156). Anodic oxidation of the potassium salt of the /8-hydroxy-carboxylic acid (158), formed by Reformat-sky reaction of the enone (157), led, also by a one-carbon ring enlargement, to a mixture of the I3y- and a/8-unsaturated ketones (159) which was converted into... 

Bicyclo[3.3.0]octanes, A37 Bicyclo[10.3.0]pentadecanes, T41 Bicyclo[5.4.0]undecanes, T12, T30 Bicyclo[7.2.0]undecanes, T28 Bile pigments, Y23 Bilobanone, T17 Binaphthyls, X6 Biotin, Y30 a-biotol, T29 Biphenyls, X3, X7 j9-bisabolene, T2 Bisepoxylignans, Y7-8 Blancoic acid, Y12... 

Brassicolene is a bicyclo[12,l,0]pentadecane also related to cembrane. Discovered in 2000 in the alcyonacean Nephthea brassica, this cytotoxic derivative is the first representative of this new carbon skeleton with a cyclo-propene. Its cytotoxicity in vitro against A-549 Itmg cancer cells and P-388 leukemia cells is, respectively, ED50 3.62 and ED50 0.86p.gml (Duh et al., 2000c). Microclavatin, isolated from Sinularia microclavata of Chinese origin, is another example of a bicyclo[12,l,0]pentadecane, but with a cyclopropane. 

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