The synthesis of single enantiomers of trans-alkene containing mycolic acids and related sugar esters

Abstract

The synthesis of single enantiomers of trans-alkene containing mycolic acids and related sugar esters, Tetrahedron (2016),

CD1b-restricted GEM T cell responses are modulated byMycobacterium tuberculosismycolic acid meromycolate chains

“…Mycolic Acid preparation and formulation MA and their sugar esters were prepared as described previously (32,(49)(50)(51)(52)(53)(54). Table S1 provides structural information.…”

Structure-Based Drug Design of ADRA2A Antagonists Derived from Yohimbine

“…Because the preparation of yohimbic acid esters by the above-described synthetic route using alcohols with the hydroxy group attached directly to a four-membered cycle proved to be problematic, a different synthetic approach was needed. N -Boc-protected amino alcohols were converted into alkylating agents using mesyl chloride and subsequently treated with the cesium salt of yohimbic acid ( 2 , Scheme ) according to described procedures. , Removal of protecting groups and reaction workup were performed in the same way as above. This approach afforded good yields of target compounds 4m – 4q (Scheme ), and their purification was also found to be easier.…”

Mycobacterium alvei (ω-1)-methoxy mycolic acids: Absolute stereochemistry and synthesis

“…The R-alcohol 14 was first brominated and then treated with triphenylphosphine to give phosphonium salt 17. This was coupled to 15-tetrahydropyranyloxypentadecanal (18) in a Wittig reaction to provide the chain extended Z-alkene (19), which was further converted into the sulfone 20 using standard transformations (Scheme 3): Coupling of the sulfone with the protected aldehyde 21 using KHMDS, 48,49 with retention of the absolute stereochemistry of the adjacent methyl substituent, as described for the preparation of trans-alkene keto-and methoxy-MA, 48 gave the diene 22. Removal of the silyl protecting group led to the methyl ester 23, which in turn was hydrolysed to the free acid 24 (Scheme 4): In the same way, the S-enantiomer of alcohol 14 was converted into the epimeric acid 25.…”