Modified McMurry coupling

In the laboratory of T. Nakai, the asymmetric tandem Claisen-rearrangement-ene reaction sequence followed by a modified McMurry coupling was used to access (+)-9(11)-dehydroestrone methyl ether. The Claisen-ene product was subjected to ozonolysis and epimerization to the 8,14-anf/ configuration. The C-ring was constructed by treating the tricyclic diketo aldehyde with TiCl3-Zn(Ag) in DME to afford the desired final product in 56% yield. 

Stereoselective McMurry coupling. Clive and co-workers1 report that a modified McMurry reagent prepared in DME with C8K and TiCl3 ( 2 1) can effect highly stereoselective coupling of keto aldehydes. Thus the key step in a synthesis... 

A variety of natural products have been synthesized via application of reductive pinacolic couplings. An early example is the cyclization of the keto aldehyde (51) to the alkene (52 equation 89) a precursor to the terpene, cuparene (18).A modified McMurry procedure provides a novel route to steroids such as estrone methyl ether, via chemoselective cyclization of the keto aldehyde (53 equation 90). The... 

Acetals, toluenesulfonates, esters, and ethers The compatibility of these groups with the McMurry reaction is illustrated by the coupling products of substituted cycloalkanones, 23 [4] and 24 [39], and benzaldehydes, 25 and 26 [40, 41] (Figure 6.4). However, benzylidene acetals were found to be cleaved in a modified McMurry reaction (see Section 6.2.6). 

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