CLL double ylide

Transition Metal Complex of the CLL Double Ylide C(PMeR2)(SPh2). 82... 

Table 2 shows those double ylides or related compounds for which transition metal complexes A CL2 or A CLL are known. A more detailed description of the divalent carbon(O) compounds in Table 2 which act as ligands in transition metal chemistry are given in the following sections. 

The Wittig reaction and its numerous derivations have undoubtedly proven to be one of the most useful and efficient methods for forming carbon-carbon double bonds . The reaction of an organophosphorus reagent with an aldehyde or ketone has also been frequently employed to extend simple dienals and dienones into more elaborate polyene systems. A key step in the convergent synthesis of the TB DMS-protected leukotriene A4 methyl ester, 19/ ,5 -Z-butyldimethylsiloxy-5S, 6S -epoxyeicosa-7 ,9 , 1IZ, 14Z-tetraenoate (43), was accomplished using a Wittig reaction between homoallylic phosphorus ylide 44 and Cl—Cll chiral epoxy dienal 45, derived from (—)-2-deoxy-D-ribose, shown in equation 29. ... 

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