Prostaglandines, three-component synthesis

Dragoli, D.R. et al.. Parallel synthesis of prostaglandin El analogues, J. Comb. Chem., 1, 534, 1999. Johnson, C.R. and Braun, M.P., A two-step, three-component synthesis of PGEl utihzation of a-iodoenones in Pd(0)-catalyzed cross-couplings of organoboranes,/. Am. Chem. Soc., 115,11014,1993. 

The challenge of three-component synthesis of prostaglandines has been met by Ryoji Noyori et /. with extraordinary success. The assembly of the "lower" ((d) and the "upper" (a) side chain is accomplished in a "one-pot" protocol. The (D-side chain is attached by addition of (5)-/raiw-3-terr-butyldimethylsiIyIoxy-l-octenyllithium complexed with one equivalent of dimethylzinc or, alternatively, with copper iodide and tributylphosphine. To install the a-chain, the zinc enolate formed in the preceding step is directly condensed with the functionalized cts-allylic or propargylic part, whereas the copper enolate has to be added in the presence of triphenyltin chloride and hexamethylphosphoric acid triamide (HMPA). ... 

Scheme 5. Larock s palladium-promoted, three-component coupling strategy for prostaglandin synthesis.

A short synthesis of prostaglandin derivatives via a three component coupling reaction is reported, in which the enolates are trapped with nitroalkenes. The nitro group is removed via... 

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