TY - JOUR
T1 - [Au]/[Ag]-catalysed expedient synthesis of branched heneicosafuranosyl arabinogalactan motif of Mycobacterium tuberculosis cell wall
AU - Thadke, Shivaji A.
AU - Mishra, Bijoyananda
AU - Islam, Maidul
AU - Pasari, Sandip
AU - Manmode, Sujit
AU - Rao, Boddu Venkateswara
AU - Neralkar, Mahesh
AU - Shinde, Ganesh P.
AU - Walke, Gulab
AU - Hotha, Srinivas
PY - 2017/1/25
Y1 - 2017/1/25
N2 - Emergence of multidrug-resistant and extreme-drug-resistant strains of Mycobacterium tuberculosis (MTb) can cause serious socioeconomic burdens. Arabinogalactan present on the cellular envelope of MTb is unique and is required for its survival; access to arabinogalactan is essential for understanding the biosynthetic machinery that assembles it. Isolation from Nature is a herculean task and, as a result, chemical synthesis is the most sought after technique. Here we report a convergent synthesis of branched heneicosafuranosyl arabinogalactan (HAG) of MTb. Key furanosylations are performed using [Au]/[Ag] catalysts. The synthesis of HAG is achieved by the repetitive use of three reactions namely 1,2-trans furanoside synthesis by propargyl 1,2-orthoester donors, unmasking of silyl ether, and conversion of n-pentenyl furanosides into 1,2-orthoesters. Synthesis of HAG is achieved in 47 steps (with an overall yield of 0.09%) of which 21 are installation of furanosidic linkages in a stereoselective manner.
AB - Emergence of multidrug-resistant and extreme-drug-resistant strains of Mycobacterium tuberculosis (MTb) can cause serious socioeconomic burdens. Arabinogalactan present on the cellular envelope of MTb is unique and is required for its survival; access to arabinogalactan is essential for understanding the biosynthetic machinery that assembles it. Isolation from Nature is a herculean task and, as a result, chemical synthesis is the most sought after technique. Here we report a convergent synthesis of branched heneicosafuranosyl arabinogalactan (HAG) of MTb. Key furanosylations are performed using [Au]/[Ag] catalysts. The synthesis of HAG is achieved by the repetitive use of three reactions namely 1,2-trans furanoside synthesis by propargyl 1,2-orthoester donors, unmasking of silyl ether, and conversion of n-pentenyl furanosides into 1,2-orthoesters. Synthesis of HAG is achieved in 47 steps (with an overall yield of 0.09%) of which 21 are installation of furanosidic linkages in a stereoselective manner.
UR - http://www.scopus.com/inward/record.url?scp=85010720956&partnerID=8YFLogxK
U2 - 10.1038/ncomms14019
DO - 10.1038/ncomms14019
M3 - Article (Academic Journal)
C2 - 28120821
AN - SCOPUS:85010720956
VL - 8
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
M1 - 14019
ER -