1.7.9- Decatriene intramolecular

The intramolecular Diels-Alder reaction of 2-methyl-( , )-2,7,9-decatrienal catalyzed by the CBA catalyst 3 proceeds with the same high diastereo- and enantio-selectivity [5d] (Scheme 1.6). 

Brmsted acid-assisted chiral Lewis acid 8 was also applied to the intramolecular Diels-Alder reaction of an a-unsubstituted triene derivative. ( , )-2,7,9-Decatrienal reacts in the presence of 30 mol% of the catalyst to afford the bicyclo compound in high yield and good enantioselectivity [lOd] (Scheme 1.17). 

Intramolecular Diels-Aldet cyclizadons of fE -Tnitro-l,7,9-decatrienes under thermal con-didons and Lev/is acid conchdons lead to the formadon of decahn ring systems with excellent aiido selecdvity fEq 8 21 This strategy is used for preparing of the AB ring system of norzoanthamine "... 

The metathesis of acyclic alkadienes and higher polyenes may involve both inter- and intramolecular processes. An example of an intermolecular reaction is the conversion of 1,5-hexadiene into 1,5,9-decatriene and ethene ... 

LP-DE also promotes and accelerates intramolecular Diels-Alder reactions of low reactive polyenones. The use of a catalytic amount of camphorsulfonic acid (CSA) further accelerates the cycloaddition and enhances the diastereo-selectivity [41]. Table 6.7 illustrates the effect of CSA on the intramolecular Diels-Alder reaction of 2-methyl-l,7,9-decatrien-3-one. 

Table 6.7 Intramolecular Diels-Alder reaction of 2-methyl-l,7,9-decatrien-3-one...

P. Herczegh, M. Zsdby, L. Szil gyi, Z. Dinya, and R. Bogndr, High diastereoselectian in the intramolecular Diels-Alder reaction of sugar-based 1,7(BZ),9-decatrienes, Tetrahedron 45 5995 (1989). 

Decatrienes, in intramolecular Alder-ene reactions, 10, 578 Dechlorination reactions, via cobalt(III) complexes, 7, 44 Decomposition pathways mixed metal carbonyls, via sonochemistry, 1, 310 in mononuclear ruthenium and osmium alkenyl formations, 6, 405... 

Intramolecular coupling with nickel tetracarbonyl has found application in syntheses of 4,5-m-humulene (XI) (19), 1,6-dimethyl-1,5,9- cyclodo-decatriene (XII) (20), and 1,4,7-trimethylenecyclononane (XIII) (21) from... 

The increased stereoselectivity of decatrien-3-ones relative to the n(matrien-3-ones may also be the consequence of cooperativity between twist asynchronicity and endo stabilization that both favor the c -fused product. The decatrien-3-one transitirm state is considerably less strained than the nonatrien-3-one transition state, and the uncatalyzed decatrienone cyclizations occur at or near ambient temperature. Consequently, one expects greater endo stabilization, and hence also greater cis stereoselectivity, in the decatrienone intramolecular Diels-Alder reactions. 

D.R. Williams et al. successfully synthesized the AB ring system of norzoanthamine by the intramolecular DIels-Alder cycllzatlon of an ( )-1-nitro-1,7,9-decatriene. The key transformation for establishing the quaternary stereocenter at C12 in the cycloaddition precursor was the Eschenmoser-Clalsen rearrangement. 

Williams, D. R., Brugel, T. A. Intramolecular Diels-Alder Cyclizations of (E)-1-Nitro-1,7,9-decatrienes Synthesis of the AB Ring System of Norzoanthamine. Org. Lett. 2000, 2,1023-1026. 

An enantioselective intramolecular Diels-Alder reaction of a-unsubstituted 2,7,9-decatrienal afforded the corresponding bicychc aldehyde in high yield and... 

A conceptually different synthetic approach to substituted derivatives of (7f)-l, 7,9-dccatrien-3-one has been described23 Reaction of silyloxycyclopropanc-containing trienes with hydrogen fluoride gave (, )-l,7,9-decatrien-3-one derivatives, which underwent intramolecular [4 + 2] cycloaddition under various conditions. 

The conjugated trienes cis. trims,cis-1,3,5-cyclodccalriene (16) and cisjrans,3,5-cycloun-decatriene (17) thermally isomerize with stereospecific formation of the tricyclic alkenes trans-tricyclo[5.3.0.04,6]dec-2-ene (18) and rrany-tricyelo[5.4.0.04-6]undec-2-ene (19) by reactions involving [1,5] sigmalropic hydrogen shifts followed by intramolecular [4 + 2] cycloadditions98. 

Tab. 2.8. Volume data of the intramolecular Diels-Alder reactions of nonatriene (E)-42 and decatriene (f )-45.

The purely thermal processes that are involved include the formation of cw-9,10-dihydronaphthalene (C9,10) from bullvalene (BV), bicyclo[4.2.2]decatetrene (422) and its intramolecular Diels-Alder adduct, tetracyclo[4.4.0.0 0 ]decadiene (TCD), from lumibullvalene (LBV), isobullvalene (IBV), tricyclo[5.3.0.0 ]deca-3,5,9-triene (TDT), and isolumibullvalene (ILBV), from basketene (BSK), NHC, TRQ, and the syn and anti isomers of tricyclo[4.4.0.0 ]decatriene (S and A, respectively), and from all c/ -cyclodecapentaene (C5), snoutene (SNT), and diademane (DIA). A more recent review includes many heats of formation and enthalpies of activation ... 

Dai and coworkers [20] studied the Wittig/intramolecular Diels-Alder (Wittig-IMDA)cycloaddition of ester-tethered 1,3,9-decatrienes 3 possessing a carbonyl substituent at Cll under controlled microwave heating in MeCN, at 180°C (Scheme 12.1). 

A synthesis of bicyclo[5.3.0]decatrienes through a Rh(I)-catalysed cycloisomerization of 3-acyloxy-4-ene-l,9-diynes has been reported " to proceed by [l,2]-acyloxy migration, 6n electrocyclization, migratory insertion, and reductive elimination. The overall process viewed as a intramolecular 5 -I- 2-cycloaddition with concomitant [l,2]-acyloxy migration (Scheme 146). 

Chiral thiopyran derivatives have been obtained in Diels-Alder reactions from monosaccharide O-thioformates and dithiooxalates. Intramolecular Diels-Alder cyclization of 1,6,8-nonatrienes and 1,7,9-decatrienes prepared from pentoses or D-glucose afforded multichiral hexahydroindene and octahydronaphthalene derivatives with very high diastereoselectivity. 

Intramolecular Diels-Alder (IMDA) reactions of 1,6,8-nonatrienes and 1,7,9-decatrienes have been used frequently for the construction of chiral ring systems of complex natural products (18-20), Although saccharide derivatives have been employed many times in intermolecular Diels-Alder reactions (21-28) their IMDA reaction appears not to have been studied so far. The diastereoselectivity of IMDA reactions can be influenced, among other factors, by the size of substituents, and by the chirality of carbons of the connecting chain. Our aim was to study the possibilities of the application of single monosaccharides as tether chains in IMDA reactions. The influence of the presence of three or four chiral... 

There are several examples of catalyzed aromatic cycloadditions leading to heterocyclic systems. The rhodium(II) acetate-catalyzed intramolecular Buchner reactions of iV-benzyldiazoacetamides 64a/b afford azabicyclo[5.3.0]decatrienes 66a/b in excellent yields. In contrast, the N-methyl derivative 64c gives 66c in moderate yield. Use of rhodium(II) perfluorobutyrate (Rh2(pfb)4) in place of rhodium(II) acetate increases the yield to 54%. Unlike its carbon counterpart, dihydroazulenone 29a (vide supra), 66a is insensitive to either trifluoroacetic acid or boron trifluoride etherate, even in excess, and the unrearranged reactant is recovered intact even after prolonged treatment at room temperature. 

Williams, D.R. and Brugel, TA. (2000) Intramolecular Diels-Alder cyclizations of ( )-l-nitro-l,7,9-decatrienes synthesis of the AB ring system of norzoanthamine. Org. Lett., 2, 1023-1026. 

Microwave-assisted tandem Witting intramolecular Diels-Alder cycloaddition of ester tethered 1,3,9-decatrienes to give 3,4,4a,7,8,8a-hexahydroisochromen-1-ones was reported with high yields (53-89%) (Wu et al., 2011). Three consecutive carbon-carbon bonds in the end product were formed rapidly during this tandem process under the microwave irradiation efficiently. 

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