A. Arasappan et B. Fraserreid, N-PENTENYL GLYCOSIDE METHODOLOGY IN THE STEREOSELECTIVE CONSTRUCTION OF THE TETRASACCHARYL CAP PORTION OF LEISHMANIA LIPOPHOSPHOGLYCAN, Journal of organic chemistry, 61(7), 1996, pp. 2401-2406
Efficient and high yielding stereoselective assembly of the tetrasacch
aryl cap region of the lipophosphoglycan from the protozoan parasite L
eishmania using the n-pentenyl glycoside protocol is described in this
paper. Both convergent and linear syntheses lead to the protected tet
rasaccharide 14; however, the convergent assembly is more efficient in
terms of product recovery. Regioselective reductive cleavage of benzy
lidene acetal 4 with triethylsilane-trifluoroacetic acid system libera
tes the required C-4 OH in excellent yield, without affecting the resi
dent chloroacetate functionality.