Ring contraction reactions of 2-O-methanesulfonates of α-hydroxy-γ-lactones in aqueous medium to oxetane-2-carboxylic acids: A convenient synthesis of 3′-O-methyloxetanocin and a formal synthesis of oxetanocin
作者:Anil K. Saksena、Ashit K. Ganguly、Viyyoor M. Girijavallabhan、Russell E. Pike、Yao-Tsung Chen、Mohindar S. Puar
DOI:10.1016/0040-4039(93)88027-g
日期:1992.12
thiohydroxamic ester 17 directly provided the key oxetanosyl-thiopyridyl glycosides 18 which were successfully coupled to N-benzoyladenine. A two-step ring contraction of the tosylate 7 to the oxetane-2-carboxamide 23 is described. Attempted ring contraction of the triflate 24 gave the unexpected products 25 and 26. A ringexpansion reaction (e.g. 14a → 21a) was also observed.