Bidirectional chain synthesis

Strikingly, this unique technique of enzymatic bidirectional chain synthesis leads in most cases to enantio- and diastereomerically pure higher-carbon diketoses of high structural complexity from rather simple a,co-dialdehydes with good... 

However, an excellent reagent-controlled cyclopropanation was observed if the stere-ogenic center was located at the other allylic position (equation 88). This reaction was used extensively in the bidirectional chain synthesis of the poly(cyclopropane) natural... 

In the chemical synthesis of complex natural products, the concept of bidirectional chain synthesis has also been shown effective for the bi-directional backbone extension, as implemented by DHAP-dependent aldolases.37 As such, highly complex carbohydrate mimics may be obtained in a single pot... 

The reaction can also be used in bidirectional chain synthesis to generate bis(cyclopropyl) derivatives simultaneously (eq 2 and 3). This reaction was used as the key step for elaboration of the poly cyclopropane natural products FR-900848 and U-106305. 

Applications of bidirectional chain synthesis to the generation of disaccharide mimetics using tandem enzymatic aldol additions, including racemate resolution under thermodynamic control. 

Bidirectional chain extension for synthesis of anulated and spirocyclic oligosaccharide mimetics by DHAP aldolase catalysis. 

A symmetric oligomer chain elongation approach was introduced by Tour et al. [168-170]. This group developed a bidirectional approach to the solid phase synthesis of oligo phenylene ethynylenes (Scheme 7.8). 

Solid-Phase Synthesis Using Side-Chain Functionalities for Attachment to Polymers and Bidirectional Extension... 

Solution phosphotriester syntheses have usually been performed by blockwise chain-elongation. The strategy of using recyclable, bidirectionally applicable (47) blocks may help to reduce the cost and facilitate the separations. Eventually, solution and support synthesis may join efforts, the latter providing for a rapid assemblage of solution-synthesized blocks—the problems, which still remain to be solved, have been discussed in Section 2. The reverse option of joining support-synthesized blocks in solution (224) seems realizable in view of recent developments (225,226) however, this alternative will probably be limited to special applications. 

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