Synthesis of a novel inosine derivative from ligia exotica

Abstract

During the study on the biologically active compounds from Ligia Exotica a novel inosine derivative was isolated and then purified by HPLC on GS 320 and ODS column. It was expected to be 3``-O-Glucosyl inosine on the basis of various spectroscopic analysis. The novel inosine derivative was synthesized by the coupling of benzylated glucosyl trichloroimidate with $^1N$-Benzyl-5``-O-acetyl inosine in the presence of $BF_3OEt_2$. But this synthetic route exposed some problems such as low chemical yield, and poor regio-, stereoselectivity. In an effort to circumvent these shortcomings new synthetic access has been developed. For the preparation of selective glycosyl acceptor t-Butyldimethyl silyl(TBDMS) protecting group was introduced to inosine. Then, the glycosylation of a O-(2,3,4,6-tetra-O-benzyl-α-glucosyl) trichloroimidate to a $^1N$-Benzyl-2``,5``-di-O-TBDMS inosine gave satisfactory result in the aspects of chemical yield and regio-,stereo- selectivity of a required α isomer. ◁그림 삽입▷(원문을 참조하세요)