An efficient and cost-effective preparation of di-O-acetyl-d-rhamnal

Abstract

We have developed a synthetic route to the frequently utilized deoxysugar building block di-O-acetyl-D-rhamnal originating from the inexpensive starting material methyl α-D-glucopyranoside. Our approach proceeds in five steps with minimal column chromatography purification needed to afford the title compound in good overall yield. 2009 Elsevier Ltd. All rights reserved.

Preparation of a 1,2-isoxazolidine synthon for the synthesis of zetekitoxin AB

“…6 According to methods developed by Bernet and Vasella, reductive fragmentation of 4 with zinc in refluxing ethanol gave the aldehyde 5 . 7 Without further purification, the aldehyde was condensed with p -methoxybenzylhydroxylamine to afford the nitrone.…”

“…5 It is known that the pyrrolidine ring in STX is derived from arginine and thus likely the same in ZTX and further unlikely that nature elaborates this ring until late in its production. 6 Since C10 in STX is oxidized one could imagine that enol/keto tautomerization produces a high enol content at C11 and this reacts with an electrophilic carbon at C14 in the biosynthesis of ZTX (Figure 1). Herein we describe the synthesis of a suitably protected 1,2-isoxazolidine derivative, with the correct carbon framework, to explore this strategy for the synthesis of ZTX.…”