Asymmetric Catalysis Route to anti,anti Stereotriads, Illustrated by Applications

Stereoselective Synthesis of a Protected Side Chain of Callipeltin A

Matteson homologations of chiral boronic esters proved to be an excellent tool for the synthesis of highly functionalized amino and hydroxy acid residues. This method provides straightforward stereoselective access to the side chain of callipeltin A, a natural marine product with interesting biological activities. Furthermore, this protocol should allow for variations in the substitution pattern in future SAR studies, simply by choosing suitable nucleophiles during the homologation steps.

Synthesis of the cyclic heptapeptide core of callipeltin A

Macrolactonisation of a suitable heptapeptide precursor provides the cyclic depsipeptide core of callipeltin A in excellent yield.

A multifunctional divergent scaffold to access the formal syntheses of various sesquiterpenoids

The development of a divergent scaffold able to access an array of diverse natural sesquiterpenoids is described. The route unifies the scope of previously reported plans of our group to allow the scalable synthesis of 8,12-furo and lactone sesquiterpenoid carbocyclic cores of elemanes, germacranes, guaianes, cadinanes, lindenanes and myliols. The formal syntheses of furogermenone, methyl-curdionolide, zedoarol, qweicurculactone, lindenene and sarcandralactone A are reported.

Stereoselective construction of all-anti polypropionate modules: synthesis of the C5-C10 fragment of streptovaricin U

A concise nonaldol approach for the stereoselective construction of all-anti polypropionate fragments was developed. The iterative epoxide-based methodology consists of the syn-selective epoxidation of cis homoallylic alcohols with use of the VO(acac)(2)-catalyzed conditions followed by epoxide cleavage with a propynyl aluminum reagent as key steps. The methodology was applied to the synthesis of the all-anti C6-C10 fragment of streptovaricin U.