Organocuprates alcohol synthesis

Epoxide opening. A stereoselective alkene synthesis starts from reaction of triethylsilyloxirane with an organocuprate reagent, and it is concluded by oxidation of the j8-silyl alcohol to the aldehyde, Grignard reaction and elimination of [Et Si/OH]. The elimination leads to either the ( )- or the (Z)-alkene by using different reagents. 

In an application from the area of prostaglandin synthesis, the protected 1-iodopropargyl alcohol 164 was reduced to the (Z)-iodoolefin 165, which was subsequently converted via 166 into the functionalized organocuprate reagent 167. The latter then provided the IS-cis-pro-staglandin 168 by a highly stereoselective conjugate addition to the appropriate cyclo-pentenone derivative [111] (Scheme 2-18). 

Reaction of the alkenyl iodide with a lithium organocuprate, or with an organometallic species in a palladium-catalysed coupling, gives the corresponding substituted allylic alcohol (in which the substituents originally present in the propargylic alcohol are trans to each other). This method is applicable to a variety of synthetic problems in which the stereoselective introduction of a trisubstituted carbon-carbon double bond is involved. For example, it formed a key step in a synthesis of juvenile hormone (2.64). 

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