Tricyclo decane group

The skeleton of 47 is a heterocyclic tricyclo[6.2.0.0 ]decane and the similarity to the tricyclic kelsoene is obvious. In the course of the above-mentioned studies we had become curious whether the high facial diastereocontrol in the photocycloaddition reaction could be extended to other bridged 1,6-hexadienes. Kelsoene was an ideal test case. The retrosynthetic strategy for kelsoene along an intramolecular [2+2]-photocycloaddition pathway appeared straightforward. To avoid chemoselectivity problems the precursor to kelsoene should not contain additional double bonds. Alcohol 48, the hydroxy group of which was possibly to be protected, seemed to be a suitable substrate for the photocycloaddition (Scheme 14). Access to the 1,2,3-substi-... 

The construction of the tricyclo[5.2.0.02,6]nonane (26, n = 1) and tricyclo[6.2.0.02,7]decane (26, n = 2) frameworks involved the [2 4- 2] cycloaddition of readily accessible31,32 l,2-bis(trimethyl-siloxy)cyclobutene and cnone 25, n = 1 or 2, respectively.33 The yields (75-80%) were good for adducts 26a, c, e, and g. Lower yields (40-50%) were observed for adducts 26b and 26f, while adduct 26d was only isolated in a trace amount. The most interesting and important reaction, related to the total synthesis of eudesmane sesquiterpenes, was the photochemical reaction of (-)-piperitone (25g) with l,2-bis(trimethylsiloxy)cyclobutene, which gave c/.v,(5wf/u W-2/j,7/i-dimethyl-4/ -isopropyl-l f ,8Jf -bis(triniethylsiloxy)tricyclo[6.2.0.0z 7]dec-3-one (26g) with the relative cis configuration of the methyl (R2) and isopropyl (R3) groups.33,34 Some of the other photochemical [2 + 2] cycloaddition reactions utilizing l,2-bis(trimethyl-siloxy)cyclobutene are shown by the formation of 2735,36 and 28.37... 

An electrochemical procedure for the replacementofcarboxyl function by an acetoxy group at the C-2 carbon atom of a tricyclo[4.4.0.01,s]decan-4-one system has been realized 90 . The procedure is utilized as the key step for the synthesis of cubebol 114... 

Deprotonation of the dication cij-1,6-dimethyl-l,6-diazoniabicyclo[4.4.0]decane (66) results in products derived from deprotonation at a methyl group, including 1-methyl-l-azonia-6-bicyclo[4.4.1]undecane (67) <84JCS(P2)4ll, 86J0C3169>, and deprotonation of the dication of 6-methyl-l,6-diazoniatricyclo[6.2.2.0 ]dodecane (68) affords the monoion of 1-methyl-l-azonia-6-aza-tricyclo[7.2.1.0 "]dodecane (69) <86JOC3i69>. 

Similarly the bicyclic cyclopropyl ketone 134 is readily converted to the tricyclo[5.3.0.0 - ]decane 135 under similar conditions via a domino ring opening/Michael/aldol reaction sequence as shown in the Scheme 4.27 [45]. The selective attack of the iodide ion at the 6-position of 136 leading to the intermediate 137 may be due to the effective overlap between cleaved bond and the % orbital of the carbonyl group. This novel domino reaction producing polycyclic cyclobutanes was exploited for the synthesis of natural products like ( )-anthoplalone and ( )-lepidozene by the same workers [45]. 

Diamondoid molecules are cagelike saturated hydrocarbons. These molecules are ringed compounds, that have a diamondlike structure consisting of a number of six-member carbon rings fused together. They are called diamondoid because they can be assumed as repeating units of the diamond. The most famous member of this group, adamantane, is a bicyclic saturated hydrocarbon (tricyclo [3.3.1.1]decane). 

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