3-Trimethylsilyl-cyclooctene

Alkyl hydroperoxides react with Af,Af-bis(trunethylsilyl)acetamide to give alkyl hydro-peroxysilanes. For example, 3-hydroperoxycyclopentene, -cyclohexene and -cyclooctene react with Af,Af-bis(trimethylsilyl)acetamide in a 2 1 mole ratio to yield the corresponding trimethylsilyl cycloalkenyl peroxide 17 (equation 27). ... 

Q2lr2C32H3g, Iridium, di- -chloro-bis[bis(cyclooctene)-, 28 91 QgLaLiOjSigCgoHjg, Lanthanum, bis[tf -13-bis(trimethylsilyl)-cydopentadienyl]di-fi-diloro-bis(tetrabydraiuian)lithium-, 27 170 CljLagSigCggHgg, Lanthanum, tetrakis[it -13-lNs(trinmthylsilyI)cydopentadienyl]-di-fi-chloro-di-, 27 171 02LiNd02Si4C3gH, Neodymium,... 

Treatment of diiododerivative of dibenzo[a,e]cyclooctene (entry e, Table 24.25) with 1 equiv of 6-terf-butyldimethylsilyl-8-trimethylsilyl-3-methyl-3-(Z)-octen-l,7-diyn-5-ol (ca. Scheme 24.30) produces the monocoupling adduct, which on treatment with KH yields the corresponding Z,Z-diendiyne. The cascade sequence triggered by THAT affords the diiodide derivative of tris-dibenzo[a,e]cyclooctene. The reactions sequence is outlined in Scheme 24.35 [10]. 

Consequently,6-tert-butyldimethylsilyl-8-trimethylsilyl-3-methyl-3-(Z)-octe-ne-l,7-diyn-5-ol serves as a latent diendiyne moiety, which on cross-coupling with aryliodides provides an easy access to a variety of diendiynes, (Z,Z)-l-aryl-3,5-octadiene-l,7-diynes. These diendiynes are precursors of 5,6-diaryldibenzo[a,e] cyclooctenes. The generation of two diendiynyl moieties (tetraentetraynes) in the same molecule produces oligomers having multiple dibenzo[a,e]cyclooctenyl units. 

MO studies have shown that the Diels-Alder reaction of substituted selenocar-bonyl compounds with buta-1,3-diene or 2-methoxybuta-1,3-diene proceeds through a concerted, asynchronous transition state. Q ,jS-Unsaturated seleno ketones and seleno aldehydes readily undergo 4 - - 2-cycloaddition with alkenes and 4 - - 2-dimerization. The reaction of phosphaacetylene (138) with buta-1,3-diene produces triphosphatri-cyclooctenes (139) through a sequence involving Diels-Alder, ene, and intramolecular 4 -I- 2-cycloadditions (Scheme 53). The 4 + 2-cycloaddition of phosphaalkynes with 5,8-bis(trimethylsilyl)cycloocta-l,3,6-triene (140) readily yields the tricyclodecadiene (142) via the bicyclic intermediate (141) (Scheme 54). "... 

Transformation of an alkenylsilane to a 1,2-dihydroxyalkylsilane, followed by the Peterson reaction after conversion of its a-hydroxy group to methoxy group, provides a useful method for the stereoselective synthesis of an alkene. 1-Methoxy-fraus-cyclooctene 201 is prepared by syn-elimination from )S-hydroxyalkylsilane 200, which is derived from syn-dihydroxylation of 1-trimethylsilyl-cis-cyclooctene, although the product 201 is thermally unstable and easily isomerizes to the cis-cyclooctene (Scheme 2.127, for NMO, see Scheme 2.27) [356]. 

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