Cyclodeca-l,6-diene

In competition experiments, using Re20v as catalyst, CDT is considerably less reactive than CHT, CEP or cyclooeta-1,5-diene (COD) (Saito 1979). It appears that, like cw,cw-cyclodeca-l,6-diene (see Section 12.8), this particular ring is more stable than the others. Yet it can act as a cocatalyst, when used in small quantities with WClfi, for the ROMP of COD (Kupper 1979). 

Decalin derivatives were obtained from cis,ci5-cyclodeca-l,6-diene on bromination with one mole of bromine. Tri-isobutyl aluminium catalysed the rearrangements of CIS,trans-cyclodeca-1,5-diene and 9-methyl- and 9-phenyl-cis,trans-cyclodeca-1,5-dienes to ds-1-methyleneperhydroindan and mixtures of methyl- and phenyl-ds-1-methyleneperhydroindans, respectively. ... 

Z,Z-Cyclodeca-l,6-dienes have been prepared from the bis-allylic bromide (240) (Scheme 22) by coupling with dimethyl malonate or the formaldehyde dianion equivalent, TosMIC yields are around 60%, when high-dilution conditions are used. In related work, it has been shown that 2-(malonic esters can be cyclized intramolecularly in moderate yield using EtOK and 18-crown-6 in very dilute DMSO solutions. ... 

General Systems.—Allinger et al. have applied the force-field method to calculations of the energy and conformation of cyclic non-conjugated olefins, including cycloheptene, isomeric cyclo-octeries, cyclo-octadienes, and cyclo-decenes, and cis,cis-cyclodeca-l,6-diene the latter is predicted to exist as a 65 35 chair-boat mixture. Similar calculations have been carried out for various cyclic ketones. Cycloheptanone is expected to exist as a mixture of conformers, whereas cyclo-octanone and cyclononanone should exist as (1) and (2), respectively. The conformation (3 X = Hj) predicted for cyclo-... 

Treatment of 61 with silver(I) perchlorate in methanol afforded (Z,Z)-l,6-dibromo-5,9-dimethoxycyclodeca-1,6-diene (63), which was readily converted into a cyclodeca-l,6-diyne derivative 64. ... 

The silver-nitrate-catalysed cyclopropyl-allyl rearrangement of (451) has been used in the preparation of benzazocines and, by ring expansion of (452) with silver acetate-acetic acid, the two substituted trflns,cis-cyclonona-dienes have been made. The trans,trflns-cyclodecadienes (454), which are involved in a synthesis of cyclodeca l,6-diyne-3,8-diol, have been prepared by... 

All-c/5-l,6-dichloro-l,3,6,8-cyclodecatetraene (123) and all-cw-l,6,6-trichloro-1,3,8-cyclodecatriene (124) were obtained by the reaction of c/j,c/j-3,8-cyclodeca-diene-l,6-dione (122) with phosphorus pentachloride . Treatment of 123 with lithium diisopropylamide led to all-cij-l-chloro-l,3,8-cyclodecatrien-6-yne (125) and naphthalene (126). The same products (125 and 126) were obtained by a similar... 

Pb-tetraacetate added portionwise with stirring and cooling below 30° during 15 min. to a soln. of frans-9,10-dihydroxy-l,4,5,8,9,10-hexahydronaphthalene (prepn. s. 182) and trichloroacetic acid in methanol, stirred 4 hrs. at room temp, until Kl/starch paper gives only a slight reaction 1,1,6,6-tetramethoxy-cyclodeca-3,8-diene (startg. m. f. 457). Y 74%. C. A. Grob and P. W. Schiess, Helv. 45, 1546 (1960). 

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