Bicyclo tetradecanes

Hydroxy-tridecan-4-olid1 —> 8-Hydroxy-tetradecan-S-olid1 —> 3-Oxo-4,4-dimethyl-2-oxa-bicyclo[3.3.0]octans 45% d.Th. 

Die kathodische Reduktion von l,4-Dibrom-bicyclo[2.2.1]heptan in DMFergibt neben Bicyclo[2.2.1]nonan (I) und Pentacyclo 4.2.2.22 sl1,bl2 s]tetradecan (II) 1-(N-Methyl-N-formyl-amino)-bicyclo[2.2.1, ]heptan (III)4 ... 

Medium-ring bicyclic diamines have now been prepared and their proton transfer behaviour has been investigated (Alder, 1983). The diamine 1,6-djflza-bicyclo[4.4.4]tetradecane [73] is reluctant to undergo outside-prptonation, presumably because outward pyramidalisation of the nitrogen atoms intro duces strain the diamine exists in the in-in conformation. The strain involved... 

In order to determine the electronic interaction between the amino and the alkene functionalities, the n and tt orbital energies of 32 and the two analogous monofunctional compounds l-azabicyclo[4.4.4]tetradecane (34) and bicyclo[4.4.4]tetradec-l-ene (35) should be known. n and JZ( =c of 32 and 34 have been determined by PES, while 7r =c of the unknown alkene 35 has been estimated. The data are depicted in Figure 9. 

FIGURE 9. Orbital correlation diagram for l-azabicyclo[4.4.4]tetradec-5-ene (32), 1 -azabicyclo 4.4.4 -tetradecane (34) and bicyclo[4.4.4]tetradec-l-ene (35)... 

A further indication that the hydrogen bond in protonated 1,6-diaza-bicyclo[4.4.4]tetradecane [49] is strong is provided by the exceptionally low acidity the pA -value is ca. 25 (Alder, 1989). In some of the other diamines, for which inside-protonated forms could not be obtained by conventional proton-transfer reactions, it was not known whether this was due to a low rate of protonation or to low basicity of the amines towards inside protonation. The estimated pX -value for [49] at least makes it clear... 

Olefination of the Aldehyde 178 using a stabilized Wittig reagent followed by protecting group chemistry at the lower branch and reduction of the a,p-unsaturated ester afforded the allylic alcohol 179 (Scheme 29). The allylic alcohol 179 was then converted into an allylic chloride and the hydroxyl function at the lower branch was deprotected and subsequently oxidized to provide the corresponding aldehyde 161 [42]. The aldehyde 161 was treated with trimethylsilyl cyanide to afford the cyanohydrin that was transformed into the cyano acetal 180. The decisive intramolecular alkylation was realized by treatment of the cyano acetal 180 with sodium bis(trimethylsi-lyl)amide. Subsequent treatment of the alkylated cyano acetal 182 with acid (to 183) and base afforded the bicyclo[9.3.0]tetradecane 184. 

Banjoo D, Maxwell AR, Mootoo BS, Lough AJ, McLean S, Reynolds WF (1998) An Unusual Erythrolide Containing a Bicyclo[9.2.1]tetradecane Skeleton. Tetrahedron Lett 39 1469... 

A new cembranoid derivative sarcophytol T (25) in addition to sarcophytol A (3), sarcophytol N (19), and sarcophytol F (10) were reported from the same species. Sarcophytol T (25) as well as its isomers sarcophytol N (19) and sarcophytol F (10) were converted by autooxidation to bicyclo [9.3.0] tetradecane derivatives, when they were kept in CHCI3 solution at room temperature. Interestingly, Konig and Wright reported a second sarcophytol T (26) isolated from an Australian sample of S. ehrenbergi von Marenzeller (Alcyoniidae, OctocoraUia) in 1998 its structure was determined by spectroscopic data and confirmed by chemical correlation (Figure 6-2). 

Many bridged ring systems are named by the von Baeyer system. Von Baeyer names are used mostly for bridged ring systems and occasionally for nonbridged ring systems. Examples of von Baeyer names are bicyclo[3.2.1]octane and tricyclo[7.4.1.0 ]tetradecane. 

To overcome the limitation of the high stability of the aluminum enolates, the oxygen atom has been transformed to silyl enol ethers, enol acetates, and allyl enol carbonates. Silyl enol ethers and enol acetates are precursors to lithium enolates. Enol acetates and allyl enol carbonates are precursors of cx-allylated adducts via the Tsuji-Trost rearrangement [75-77]. The silylation of aluminum enolates using TMSOTf is well established [78], although in some cases the isolation is difficult [33]. Silyl enol ethers allow further modification to be performed as they behave as lithium enolates (Scheme 15). A recent application can be found in the silylation of the conjugate addition adduct (/ )-((3-(but-3-en-l-yl)-3-methylcyclopent-l-en-l-yl)oxy)triethylsilane which allows aldol condensation to form an intermediate in the synthesis of Clavirolide C [79], a diterpene with a trans-bicyclo[9.3.0] tetradecane structure (Scheme 16) [80]. 

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