L-薄荷基-D-吡喃木糖苷的合成及其热稳定性研究  

Research on synthesis and thermostability of L-menthyl D-xylopyranoside

作　　者：李宏伟[1] 陈朗秋[1] 刘灯峰[1] 曾森[1] 陈静[1] 夏殊[1] 何丽萍[1] 

机构地区：[1]湘潭大学化学学院环境友好化学与应用省部共建教育部重点实验室,湖南湘潭411105

出　　处：《中南大学学报（自然科学版）》2014年第8期2577-2582,共6页Journal of Central South University:Science and Technology

基　　金：湖南省自然科学基金资助项目(14JJ2067;10JJ6023;05JJ40054)

摘　　要：为提高L-薄荷醇(e)的热稳定性,合成2种薄荷基糖苷类香料前体。以D-木糖(a)为原料,经乙酰基保护、选择性脱一位乙酰基、转变成三氯乙酰亚胺酯(d)、与L-薄荷醇(e)进行偶联,立体专一性地合成L-薄荷基-2,3,4-三-O-乙酰基-β-D-吡喃木糖苷(f)。全乙酰基-D-木糖(b)在4种路易斯酸催化下,与薄荷醇(e)直接偶联得到L-薄荷基-2,3,4-三-O-乙酰基-β-D-吡喃木糖苷f和(或)L-薄荷基-2,3,4-三-O-乙酰基-α-D-吡喃木糖苷(h),f和h分别脱保护,获得相应的L-薄荷基-β-D-吡喃木糖苷(g)和L-薄荷基-α-D-吡喃木糖苷(i)。实验结果表明:以FeCl3为催化剂,全乙酰基-D-木糖b与L-薄荷醇(e)直接偶联,立体专一性地获得L-薄荷基-2,3,4-三-O-乙酰基-α-D-吡喃木糖苷h;以BF3.Et2O为催化剂,使全乙酰基-D-木糖(b)与L-薄荷醇(e)直接反应,可较为简便地获得L-薄荷基-2,3,4-三-O-乙酰基-β-D-吡喃木糖苷(f)。薄荷基糖苷(g)和(i)经NMR,MS,TG,熔点和旋光分析得到确证。2种L-薄荷基吡喃木糖苷(g)和(i)的热稳定性均明显地比L-薄荷醇(e)的热稳定性强。In order to improve the thermostability of L-menthol（e）, two L-menthyl glycosides flavor precursors were synthesized. With D-xylose（a） as a raw material, L-menthyl 2,3,4-tri-O-acetyl-β-D-xylopyranoside（f） was stereospecifically obtained in five steps by acetylation, selective deprotection of acetyl group at the C1, conversion to corresponding trichloroacetimidate（d） and coupling with L-menthol（e）. Furthermore, with four kinds of Lewis acid as the catalyst, the direct coupling of peracetyl-D-xylopyranoside（b） with L-menthol（e） afforded L-menthyl 2,3,4-tri-O-acetyl-β-D-xylopyranoside（f） and（or） L-menthyl 2,3,4-tri-O-acetyl-α-D-xylopyranoside（h）, subsequent f or h was respectively deprotected to achieve L-menthyl β-D-xylopyranoside（g） or L-menthyl α-D-xylopyranoside（i）. The experimental results show that peracetyl-D-xylose（b） is directly coupled with L-menthol（e） to afford stereospecifically L-menthyl 2,3,4-tri-O-acetyl-α-D-xylopyranoside（h） with FeCl3 as a catalyst. With BF3.Et2 O as a catalyst, peracetyl-D-xylose（b） is directly coupled with L-menthol（e） to give rather conveniently L-menthyl 2,3,4-tri-O-acetyl-β-D-xylopyranoside（f）. The menthyl glycosides g and i are confirmed by NMR, MS, TG, melting point and optical rotation. The thermostabilities of two L-menthyl xylopyranosides g and i are obviously higher than that of L-menthol（e）.

关 键 词：L-薄荷醇 吡喃木糖苷 合成 热稳定性 

分 类 号：O629.13[理学—有机化学]