Grubbs Hydroxylated

Hydroxylation of the terminal double bond in 140 followed by the esterification paved the way to phosphodiester 141, whereas Grubbs olefin metathesis followed by hydroxylation and esterification led to divalent phosphodiester 142. 

In line with our previous experiences, diene 56 readily cyclized to the desired 19-membered ring 57 on reaction with the ruthenium carbene 2 (5 mol%) in refluxing CH2C12. The fact that neither the free hydroxyl group nor any other functionality in the substrate interfere with RCM illustrates the excellent compatibility and selectivity of the Grubbs catalyst (7). Hydrogenation of the crude cycloalkene ( -mixture) thus obtained afforded the desired disaccharide 57 in 77% yield. The elaboration of this compound into tricolorin A 46 can be achieved according to literature procedures (25). 

Tentagel, described above, is in wide use today in solid phase syntheses. Polyethylene glycol has also been attached to various other polymers to form support resins. For instance, Frechet and coworkers [37] used cross-linked methacrylate esters of ethylene glycol oligomers in a suspension polymerization to synthesize hydroxyl group functionalized beads. These beads swell well in a variety of polar solvents. Another example is that of Grubbs attaching a ruthenium metathesis catalyst to polyethylene [38] ... 

End-functionalized poly(norbornene)s capped with one or two acetoxy or alcohol groups were prepared with the Grubbs catalyst I and mixed NHC/phosphine catalysts (405). Acetoxy and hydroxyl end-capped polymers were prepared by Gibson and Okada from bis(ferf-butylester)-substituted norbomene by means of the Grubbs catalyst I. Subsequent hydrogenation of the hydroxy functionalized polymer gave the corresponding poly(norbornene) (406). 

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