‘Face‐to‐Face’‐Benzo‐anellierte homologe Hypostrophene. Synthesen, Röntgenstrukturanalysen und PE‐Spektren

Fessner, Wolf‐Dieter; Sedelmeier, Gottfried; Knothe, Lothar; Prinzbach, Horst; Rihs, Grety; Yang, Zhong-Zhi; Kovač, Branka; Heilbronner, E.

doi:10.1002/hlca.19870700718

“…C24H20N404 (428.4) Calcd. C 67.28 H 4.71 N 13.08 Found C 67.03 H 4.48 N 12.77 Photolysis of 28: 25 ml of a solution of 28 (2.0 g, 4.7 mmol) in CH2C12 (50 ml) is added to dry methanol (1 1 -14), 93.4 (C-l9), 61.7 (C-1, -2)*, 60.6 (C-11, -12)*, 58.9 (C-4), 57.5 (C-9), 57.5 (C-6, -7), 57.2 (2 OCH,),, 51.5 (COZCH,), 51.4 (CO,CH,), 44.9 (C-8, -lo), 44.8 (C-13, -15), 44.4 (C-18, -20), 44.3 (C-3, -5) 405 (14), 376 (6), 285 (6), 253 (5), 221 (7), 158 (7), 128 (6), 115 (lo), 75 (25). 2.60 (m, 13-, 15-, 18-, 20-H).…”

Section: B') Degradation With And(i) Oxidementioning

confidence: 98%

4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations

Melder

¹

,

Prinzbach

²

1991

Self Cite

View full text Add to dashboard Cite

Various 4,9,14,19-tetrafunctionalized pagodanes are prepared by a de novo route commencing from appropriately substituted isodrin analogues (3, 4). With the 14,19-dimethoxypagodane-4,9-dicarboxylic esters 30/31, isolated after 16 one-pot operations (ca. 40 functional changes) in ca. 6.5% overall yield (ca. 84% per operation, ca. 93% per functional change), the scope for further functional group manipulations on the pagodane sphere is explored (e.g. diketone dicarboxylic ester 35, dimethoxy diketone 37, tetraketone 41). In two face-to-face dibenzo substrates (17, 49), clean photoequilibration with the corresponding syn-o,o'-dibenzo isomers (19, 50) (75: 25 and 80: 20, resp.) is observed upon direct excitation (h = 254 nm).The [l.l.l.l]pagodanes play a central part in our quest for pentagonal dodecahedranes I). The Lewis-acid catalyzed transformation of the parent (CH)ZO hydrocarbons (A, B), though not sufficiently selective for extensive preparative utilization, was a first success2). Attempts to catalyze this transformation with the help of "super acids" led, instead, to the pagodane dication -the compensation being the latter's novel 2-electron o-homoaromatic ~h a r a c t e r~,~) .The way out of this dilemma, e.g. directed stepwise procedures based on the high reactivity of the central four-membered ring in A, originally implied -as in the Paquette synthesis5)-dehydrogenative transanular C-C bond formation at the bisseco-and secododecahedrane stages '). Thus experimental conditions were required, which allowed acceptable yields of the parent hydrocarbon, but posed a rather strict limitation to our early defined goal -the modification of the outer dodecahedrane sphere with diverse substitution patterns. In fact, previously incorporated functional groups generally did not survive these final bond forming procedures ' ). Yet, a broad spectrum of substituents would tolerate a variety of methods which are established for the formation of C-C bonds between sp2 or between sp2 and activated sp3 centers. The non-trivial task to appropriately functionalize the pagodane framework at all four secondary positions (C-4, -9, -14, -19) was tackled on two independent tracks: Intramolecular functionalization at C-14(-19) by making use of the syn-4,syn-9 substituents in available pagodanes (F, R' = H, R e.g. CONH,)') and de novo synthesis starting not from isodrin but from adequately functionalized isodrin analogues'). A BThe latter approach, closely patterned after the original, systematically optimized pagodane synthesis lo), is detailed in this paper and subdivided into three stages. A general route to various 11,12-difunctionalized tetracyclododecadienes of type C is described in the literature",'*). In the end, our decision for specific substituents was made primarily under the aspect of their survival under the reaction conditions applied along the total route. After extensive experimentation we settled for the synthesis as outlined in Schemes 1 and 2 with the dimethoxy-tertChem. Ber. 124 (1991) For the benzoanelation to t...

show abstract

“…U2~'X.03~7.06~1".0X~'Z.011~15.013~17.016~2 16-, 17-H), 3.02 (m, 6-, 7-H), 2.95 (m, 4-H), 2.85 (m, 9-H), 2.73 (m, 3-, 5-H), 2.50 (m, 8-, 10-H), 2.38 (m, 13-, 15-2970(C-H), 2950(C-H), 2820(C-H), 1725 (C=O), 124O(C-0), H), 2.34 (III,. -13C NMR (CDCI,, 100.6 MHz): 6 zz 173.7 (CO,CH3), 173.2 (COZCH,), 93.5 (C-14), 93.4 (C-l9), 61.7 (C-1, -2)*, 60.6 (C-11, -12)*, 58.9 (C-4), 57.5 (C-9), 57.5 (C-6, -7), 57.2 (2 OCH,),, 51.5 (COZCH,), 51.4 (CO,CH,), 44.9 (C-8, -lo), 44.8 (C-13, -15), 44.4 (C-18, -20), 44.3 (C-3, -5) 405 (14), 376 (6), 285 (6), 253 (5), 221 (7), 158 (7), 128 (6), 115 (lo), 75 (25). D i m e t h y l anti-14,anti-19-Dihydroxyundecu~yclo(Y.9.0.O'~~.O~~~~.…”

Section: B') Degradation With And(i) Oxidementioning

confidence: 99%

ChemInform Abstract: 4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis ‐ Functional Group Manipulations.

Melder

¹

,

Prinzbach

²

1991

ChemInform

0

View full text Add to dashboard Cite

Various 4,9,14,19-tetrafunctionalized pagodanes are prepared by a de novo route commencing from appropriately substituted isodrin analogues (3, 4). With the 14,19-dimethoxypagodane-4,9-dicarboxylic esters 30/31, isolated after 16 one-pot operations (ca. 40 functional changes) in ca. 6.5% overall yield (ca. 84% per operation, ca. 93% per functional change), the scope for further functional group manipulations on the pagodane sphere is explored (e.g. diketone dicarboxylic ester 35, dimethoxy diketone 37, tetraketone 41). In two face-to-face dibenzo substrates (17, 49), clean photoequilibration with the corresponding syn-o,o'-dibenzo isomers (19, 50) (75: 25 and 80: 20, resp.) is observed upon direct excitation (h = 254 nm).

show abstract

“…For comparison, the relevant structural data for several annellated derivatives of 5 are given in Table 3. 11 [42] 111 [43] IV [441 n = l n = 2…”

Section: "mentioning

confidence: 99%

The Azo(Azoxy) Functionality as a π₂ Component in Photo [2+2] cycloadditions ‘syn’‐ and ‘anti’‐3,4‐diazatricyclo[4.2.2.2^2,5]dodeca‐3,7‐diene, syntheses, photolyses, X‐ray‐structure analysis, and PE spectra

Marterer

¹

,

Prinzbach

²

,

Rihs

³

et al. 1988

Helvetica Chimica Acta

Self Cite

23

0

View full text Add to dashboard Cite

show abstract

‘Face‐to‐Face’‐Benzo‐anellierte homologe Hypostrophene. Synthesen, Röntgenstrukturanalysen und PE‐Spektren

Cited by 14 publications

References 55 publications

4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations

4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations

ChemInform Abstract: 4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis ‐ Functional Group Manipulations.

The Azo(Azoxy) Functionality as a π₂ Component in Photo [2+2] cycloadditions ‘syn’‐ and ‘anti’‐3,4‐diazatricyclo[4.2.2.2^2,5]dodeca‐3,7‐diene, syntheses, photolyses, X‐ray‐structure analysis, and PE spectra

Contact Info

Product

Resources

About

‘Face‐to‐Face’‐Benzo‐anellierte homologe Hypostrophene. Synthesen, Röntgenstrukturanalysen und PE‐Spektren

Cited by 14 publications

References 55 publications

4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations

4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis – Functional Group Manipulations

ChemInform Abstract: 4,9,14,19‐Tetrafunctionalized Pagodanes de novo Synthesis ‐ Functional Group Manipulations.

The Azo(Azoxy) Functionality as a π2 Component in Photo [2+2] cycloadditions ‘syn’‐ and ‘anti’‐3,4‐diazatricyclo[4.2.2.22,5]dodeca‐3,7‐diene, syntheses, photolyses, X‐ray‐structure analysis, and PE spectra

Contact Info

Product

Resources

About

The Azo(Azoxy) Functionality as a π₂ Component in Photo [2+2] cycloadditions ‘syn’‐ and ‘anti’‐3,4‐diazatricyclo[4.2.2.2^2,5]dodeca‐3,7‐diene, syntheses, photolyses, X‐ray‐structure analysis, and PE spectra