Tetracyclo- undecane

The synthesis of fUido-tricyclo[4.4.0.02 5]deca-3,8-dien-7,10-dione and verification of its endo-configuration has been reported earlier.3 This adduet is a useful starting material for the syntheses of tetracyclo-[5.3.0.02 6.03 10]deca-4,8-diene,s tricyclo[4.4.0.02 5]deca-3,7,9-triene,6 cis, syn, cjs-tricyclo[5.3.0.02,6]deca-4,8-dien-3,10-dione,7 and 4-oxahexa-cyclo[5.4.0.02 6.03 10.05 9.08,11]undecane.a... 

Numerous studies aimed at the understanding of the mechanism of these processes rapidly appeared. In this context, Murai examined the behavior of acyclic linear dienyne systems in order to trap any carbenoid intermediate by a pendant olefin (Scheme 82).302 A remarkable tetracyclic assembly took place and gave the unprecedented tetracyclo[6.4.0.0]-undecane derivatives as single diastereomer, such as 321 in Scheme 82. This transformation proved to be relatively general as shown by the variation of the starting materials. The reaction can be catalyzed by different organometallic complexes of the group 8-10 elements (ruthenium, rhodium, iridium, and platinum). Formally, this reaction involves two cyclopropanations as if both carbon atoms of the alkyne moiety have acted as carbenes, which results in the formation of four carbon-carbon bonds. 

Salt crystals of the benzonorbomadiene carboxylic acid 68 with optically pure triplet sensitizer amines 70, 71 also underwent enantioselective di-TT-meth-ane photorearrangement to afford the optically active tetracyclo[5.4.0.02,4.03 6]undecane derivative 69 in high enantiomeric excess [81]. The 4-acetylbenzyl ester of L-phenylalanine 70 and the 4-benzoylphenyl ester of l-valine 71 perform the dual roles of asymmetric induction and triplet energy sensitization. 

Oxa-3-thia-4-aza-tetracyclo-16.2.1.01 .04 undecan (+)-(lS,4S)-7,7-Dichloro-l 1,11-dimethyl- -3,3-dioxid E21f, 5870 (Imin-Oxid.)... 

Ethoxycarbonyl- E18, 882 (Dien + Acrylsaure-ester) Tetracyclo[4.4.1,03-11,09-11 undecan 2-Carboxy- E17e, 321 (2-Oxo— 1-N2—cyclopentan - COOH — cyclobutan)... 

Mercury(II) acetate also underwent addition across this particular bond of 9 and gave endo-tetracyclo[5.3.1,0 .0 ]undecan-3-ol (12) in excellent yield following the reduction of the primary adduct with sodium borohydride. The enrfo-product suggests the intervention of a 1,3-bridged metal ion in these reactions. 

However, this cyclopropane to propene isomerization is the only reported preparative method for the synthesis of tetracyclo[3.3.3.0. 0 ]undec-9-ene 4) from pentacyclo-[3.3.3.0 -. 0 - .0. "]undecane (13). ... 

Bis-quinoline 74 was obtained from the condensation of two equivalents of tetracyclo-[6.3.0.0. 0 ]undecane (TCXJ) 73 and o-aminobenzaldehyde 17 in 57% yields (Scheme 22) (87TL3319). 

---