The synthesis of single enantiomers of mycobacterial ketomycolic acids containing cis-cyclopropanes

Glucose monomycolates based on single synthetic mycolic acids

“…We have reported the synthesis of a range of unique mycolic acids corresponding in structure to those reported to be present in mycobacteria (Al Dulayymi et al, 2005Koza and Baird, 2007;Koza et al, 2009aKoza et al, ,b, 2013Al Kremawi et al, 2010, 2014Muzael et al, 2010). We have also reported the synthesis of the corresponding TDMs and TMMs from a range of these single mycolic acids .…”

The Synthesis of Long‐Chain α‐Alkyl‐β‐Hydroxy Esters Using Allylic Halides in a Fráter–Seebach Alkylation

“…The esters, in turn, are valuable intermediates en route to the synthesis of the immunomodulatory mycolic acids and derivatives thereof. [17][18][19][20][21][22][23]35] For example, diester 6b was selectively reduced by treatment with BH 3 ·DMS [36] to give diol 7, a versatile building block for the synthesis of lipophilic hydroxy acids. [37] Scheme 2.…”

“…[16,17] The group later developed a chainelongation strategy (involving an α-alkylation using allyl iodide followed by ozonolysis and Wittig reactions) in subsequent mycolic acid syntheses. [21][22][23] Similarly, Nishizawa et al had no success when performing a Fráter-Seebach alkylation using eicosanyl iodide on a tetracosanoyl β-hydroxy functionalised ester, however, they observed that a change of ester substrate resulted in product formation. [18] Our own attempts at an α-alkylation using eicosanyl iodide gave a disappointing 5 % yield.…”

Thiol modified mycolic acids

“…Although this was prepared simply as a model, it does represent a thiol substituted form of one of the minor mycolic acid components of Rhodococcus equi [Hsu, 2011] In order to prepare a complete thiolated mycolic acid, the intermediate (19) was first prepared. Coupling of the aldehyde (5) [Koza, 2009] with the sulfone (15) in the presence of base in a modified Julia-Kocienski reaction, followed by hydrogenation of the E/Z-mixture of alkenes obtained, then debenzylation, led to alcohol (16). This was chain extended using a similar procedure to give the aldehyde (19) (Scheme 2):…”