甲基Funlioside B的合成 甲基Funlioside B的合成

甲基Funlioside B的合成

  • 期刊名字:中國海洋大學(xué)學(xué)報(自然科學(xué)版)
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  • 論文作者:李寶杰,王鵬,謝江楓,王月佼,宋天佳,李明
  • 作者單位:中國海洋大學(xué)醫藥學(xué)院海洋藥物教育部重點(diǎn)實(shí)驗室
  • 更新時(shí)間:2020-07-04
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第44卷第2期中國海洋大學(xué)學(xué)報44(2) :085~0882014年2月PERIODICAL OF OCEAN UNIVERSITY OF CHINAFeb.,2014研究簡(jiǎn)報甲基Funlioside B的合成李寶杰,王鵬, 謝江楓,王月佼,宋天佳,李明”(中國海洋大學(xué)醫藥學(xué)院海洋藥物教育部重點(diǎn)實(shí)驗室,山東青島266003)摘要:完成呋喃甾烷型甾體皂苷甲基Funlioside B的合成。在三氟化硼乙醚促進(jìn)下,薯蕷皂苷元與乙酸酐反應以55%的產(chǎn)率得到3,16-二氧-乙?;?22-羥基膽甾烷13.以三甲基硅基三氟甲磺酸酯為促進(jìn)劑,化合物13與葡萄糖三氯亞胺酯給體11進(jìn)行糖苷化反應以83%的產(chǎn)率得到單糖苷15. 最后,在甲醇中,用氫氧化鋰脫除?;Wo基團后并在無(wú)水甲醇中回流反應,以95%的產(chǎn)率得到甲基Funlioside B。關(guān)鍵詞:甲基 Funloside B;呋甾皂苷;糖苷化;合成中圖法分類(lèi)號: R284. 3文獻標志碼: A文章編號: 1672- 5174(2014)02-085-04甾體皂苷是一類(lèi)植物中廣泛存在的次生代謝產(chǎn)性支氣管炎、乳腺炎、腮腺炎等疾病的傳統中藥一華重物[1] ,呋甾皂苷作為其中的重要組成部分[2,具有多種樓中首次分離得到的Parisaponin I 46]、和能夠抑制白生物活性53+4]。典型呋甾皂苷化合物包括1-8(見(jiàn)圖1),血病細胞MOLT-4、結腸癌細胞HCT-116、和SW-Funlioside B (1)是由dichotomin (3)經(jīng)酶Pectinex BE620..CNS癌細胞SNB-75以及腎癌細胞786-0等生長(cháng)XXL(PBX)降解得到的產(chǎn)物,對HL-60細胞顯示出一的原薯蕷皂苷和甲基原薯蕷皂苷(5和6)7]以及能增定的細胞毒性5;同時(shí)該結構亦是多種具有良好生物加C6小鼠膠質(zhì)瘤細胞的神經(jīng)生長(cháng)因子(NFG)的含量,活性呋甾皂苷的有機組成部分。如從我國用于治療慢作為治療神經(jīng)退行性疾病和糖尿病候選物的coreaja-ponin A和B (7和8) [8] 都含有Funlioside B (1)的結)R.構單元。呋甾皂苷獨特的結構和良好的生物活性,引起了合成化學(xué)家的廣泛興趣。Funlioside B(1)結構中的E環(huán)是1個(gè)半縮醛形式,22位的羥基不穩定,在微量酸性條件下,容易脫水形成雙鍵(C2o=Crz)得到偽甾體H皂苷。近年來(lái),甲基呋甾皂苷[910]相繼被分離得到,具R,OOH有較好的穩定性和良好的生物活性。因此,本文報道HO'甲基Funlioside B (2)的合成,為復雜呋甾皂苷合成提供有益的借鑒。Funlioside B 1:R1 =H,Rz=H .Methyl Funlioside B 2:R1 =H,R2 =Me1實(shí)驗部分Dichotomin 3:R1=S| ,R2= HParisaponin I 4:R1=S2,Rz=H .Protodioscin 5:R1=Ss,R2=H1.1儀器與試劑Methyl protodioscin 6:Ri = Sa ,Rz = Me所用試劑: TMSOTf、DMAP、CCl, CN、DBU均為Coreajaponin A 7:R1=S;,R2=HCoreajaponin B8:RI = S,R2= Me普通國產(chǎn)分析純試劑,直接用于反應;二氯甲烷用以氫S =arL-Rhap-(1→2)-CaL Rhap-(1→4)-rL-Rhap化鈣回流重蒸;所用石油醚為60~90°C 沸程。未經(jīng)特(1→4)]-p-D-GlcpS2=arL-Rhap-(1→2)-[aL-Araf-(1→4)]-$-D-Glcp殊說(shuō)明,其它均為普通國產(chǎn)分析純試劑。S3= arL-Rhap-(1→2)-_Ca-L Rhap-(1→4)]-9-D-Glcp柱層析使用300~400目硅膠(青島海洋化工廠(chǎng)提Sa= arL-Rhap-(1→2)-[ar1L-Araf-(1→4)]-β-D-Glcp圖1典型的呋甾皂苷化合物供);薄層用預制硅膠板型號為gel 60 F254(煙臺);Fig. 1 Typical furostanol glycosides1 H NMR、I3C NMR由JEOL JNM-ECP 600MHz核磁基金項目:國家自然科學(xué)基金項目(21002095);中國海洋大學(xué)本科生研究發(fā)展計劃項目(中國煤化工者和創(chuàng )新團隊發(fā)展計劃項目(IRT0944)資助收稿日期:2013-04-12;修訂日期:2013-05-07THCNMH G作者簡(jiǎn)介:李寶杰(1986-),男,碩士。E-mail: beidouqixing163@163. com*通訊作者: E mail: lmsnouc@ouc. edu. cn86中國海洋大學(xué)學(xué)報2014年共振波譜儀測得,四甲基硅烷(TMS)為內標,單位:(600 MHz, CDCI]3)δ5.34 (d,J=4.9 Hz, 1H), 4. 96X10-',室溫;85-2型恒溫磁力攪拌器。(m, 1H), 4.57 (m, 1H), 3. 40(d,J=5.5 Hz, 2H),1.2實(shí)驗操作2.94 (m, 1H),2.62 (m,1H),2. 42~2.34 (m,1.2.1 2,3,4,6-四-O-苯甲?;?a-D吡喃葡萄糖三氯亞2H), 2.29~2. 28 (m, 2H), 2.01 (s, 3H), 1.96~胺酯11的合成無(wú)水D型葡萄糖(10.5 g, 58. 3 mmol)1. 80 (m, 9H), 1.68~1. 22 (m, 13H), 1.11 (d,J=溶于90. 0 mL無(wú)水吡啶中,然后冷卻至0°C,氬氣保護7.1 Hz, 3H),1.00 (s, 3H), 0.89 (d,J=6.6 Hz,下點(diǎn)滴加人苯甲酰氯(40.8 ml, 350.0 mmol, 6. 03H), 0. 85 (s, 3H); 13C NMR (150 MHz, CDCI]) δequiv. ),自然升至室溫后,攪拌過(guò)夜反應,TLC(Petro-213.7,170.5, 169.8, 139.6, 122.2, 75.6,73. 8,leum ether:AcOEt = 2:1)顯示反應完全。用甲醇淬67.4,55.0, 53.8, 49.7, 43.4, 41.8, 39.5, 38. 5,滅反應,將所得溶液倒于冰水中,攪拌過(guò)夜,過(guò)濾,收集37.97,36.8, 36.5, 35.4,34.8,31.5 31.2, 27. 6,固體并用大量水洗滌得到化合物9(40.5 g, 57.726.2, 21.4, 21.1, 20.6,19.2, 16.8, 16.6,13.2;mmol, 100%),未經(jīng)表征直接投人下一步反應。HRESI-MS Calcd for Cs1 H4g O% 517.352 9,(M +化合物9(9.5 g, 13.5 mmol)溶解在60.0 mL無(wú)H)+ ; found: 517. 352 4。水THF中,然后冷卻至0°C,氬氣保護下緩慢加入甲胺化合物14:[a]B =+2.1 (c 1.1,CHClk);醇溶液(3.7 mL, 27.1 mmol, 2.0 equiv. ),自然升至H NMR (600 MHz, CDCl) δ5.36 (d,J=4.9 Hz, .室溫后,攪拌6 h后,TLC(Petroleum ether : AcOEt=1H), 4. 98 (m, 1H), 4. 59 (m, 1H), 3. 90 (m, 2H),2: 1)顯示反應完全。加人冰乙酸調pH值為5~6,減2.94 (m, 1H), 2. 67~2.29 (m, 5H), 2. 05 (s, 3H),壓蒸除溶劑,所得漿狀物使用1 mol. L-'稀鹽酸溶液2.03 (s,3H),1.95 (s,3H),1.70~ 1.24 (m,洗滌,乙酸乙酯萃取,有機相依次使用飽和的食鹽水洗18H),1.14 (d,J=7.1 Hz,3H),1.02 (s, 3H),滌,無(wú)水Na2SO。干燥,過(guò)濾收集有機相,減壓蒸除溶0.91 (d,J=6.6 Hz, 3H), 0. 86 (s, 3H)。劑,所得殘余物經(jīng)硅膠柱層析(Petroleum ether : AcO-1.2.3 (25R)-3β, 163-雙乙?;?22羰基-膽甾烷-5~烯-Et=3: 1~2: 1)得到白色固體10(5.5 g, 9.2 mmol,26 0-2,3,4,6-四-0苯甲?;?D吡喃葡萄糖苷15的68%)。合成將化合物13 (0.1 g, 0. 19 mmol),化合物11將半縮醛10(0.2g, 0.3 mmol)溶于10.0 mL無(wú).(0.21 g, 0. 29 mmol, 1.5 equiv. )和5A MS (0.6 g)水CH2Cl2中,氬氣保護下滴加CCl3CN(0.3 mL, 3. 3混溶于2.0 mL無(wú)水CH2Cl2中,室溫下攪拌30 minmmol,10.0equiv.),冰浴條件下加入DBU(10.0μL,后,在冰浴中滴加三甲基硅基三氟甲磺酸酯TMSOTf0.1 mmol, 0.2 equiv.)。室溫下攪拌4 h后,TLC(3.6 μL, 0.02 mmol, 0. 1 equiv. ),自然升至室溫攪拌(Petroleum ether : AcOEt=3: 1)顯示反應完全。減5 h后,TLC (Petroleum ether : AcOEt=1 : 1)顯示反.壓蒸除溶劑,所得漿狀物經(jīng)硅膠柱快速層析(Petroleum應完全。加人三乙胺淬滅反應。過(guò)濾掉分子篩,減壓ether: AcOEt=6: 1~5 : 1)得到白色泡沫狀固體11蒸除溶劑,所得殘余物經(jīng)硅膠柱層析(Petroleum ether :(0.2 g, 0. 3 mmol, 96%)。AcOEt=4 : 1)得到白色固體15 (0. 17 g, 0. 16 mmol,1.2. 2 (25R)-3β,16β二-0乙?;?22-羰基-膽甾烷-5-83%)。[a]B =+11.0* (c 1.0, CHCl3); 'H NMR烯26-醇13和(25R) -3β, 16β, 26-三-O-乙?;?22-羰(600 MHz, CDCl)δ8. 02 (d,J=9.1 Hz, 2H), 7. 94基_膽甾烷-5~烯14的合成將薯 蕷皂苷元化合物12(d,J=9.1 Hz, 2H), 7.90 (d,J=9.1 Hz,2H),(0.2 g, 0. 5 mmol)溶于2. 0 mL無(wú)水CH2Cl2中,冷卻7.82 (d,J=9.l Hz, 2H), 7.52~7.45 (m, 3H),至一5°C,加人乙酸酐(0.5 mL, 4.8 mmol, 10.07.42~7.22 (m, 8H),7.17 (m, 1H),5.89 (t,J=equiv. ),攪拌10 min,緩慢滴加BFs●OEt2(0.4 mlL,11.6 Hz, 1H), 5.67 (t,J=11.7 Hz, 1H), 5.52 (t,3.4 mmol, 7. 0 equiv. ) ,繼續攪拌5 min, TLC (Petro-J=11.5 Hz, 1H), 5.36 (d,J=4.8 Hz, 1H), 4. 92leum ether: AcOEt=3: 1)顯示反應完全。將反應液(m, 1H),4.81 (d,J=9.4 Hz, 1H),4. 65~4.55置于冰水中充分攪拌。所得溶液用CH2Cl2稀釋,依次(m, 2H),4.50 (dd,J=14.5, 6.2 Hz,1H), 4.15使用飽和NaHCOz溶液,飽和食鹽水洗滌,收集有機相(m,1H), 3.73 (m, 1H), 3.37 (m,1H), 2.85 (m,用無(wú)水Na2SO,干燥,過(guò)濾、減壓蒸除溶劑,所得漿狀物1H), 2.54~2. 19 (m, 6H), 2.01 (s, 3H), 1. 92~經(jīng)硅膠柱層析(Petroleum ether : AcOEt : CH2Cl2=1.81 (m, 8中國煤化工12H),1.02 (s,3:1:1)得到白色固體13(140mg,0.27mmol,.3H), 0. 99:fYHC NMH G3 (s, 3H), 0.7655%)和白色固體14 (75 mg, 0. 13 mmol, 27%)?;?d,J=7.9 Hz, 3H); 13C NMR (150 MHz, CDCl3) δ合物13:[a]”7=-0.3'(c 1.0, CHCl3); H NMR212.9,170.5,169.8, 166. 1, 165. 7, 165.2,165. 0,2期李寶杰,等:甲基Funlioside B的合成139.5,133.4, 133.2, 133. 1, 133.0,129.8, 129. 7,將異頭位的苯甲?;鶊F脫除得半縮醛10,在DBU(1,8-129.6,129.5, 129.2, 128.8,128.7,128.4,128.3,二 二惡唑雙環(huán)[5,4,0]-7-+- -烯)作用下與三氯乙腈反應128.2,122.2, 101.4, 75.6, 75.2, 73.8, 72. 9,得到2,3,4,6-四-O-苯甲?;?arD-葡萄糖三氯亞胺酯72. 1, 71.8, 69.8, 63.1, 54.9, 53.8, 49.7, 43.4,給體11 (Scheme 1) ,其數據與文獻[11]報道- -致,為41.8, 39.5,38.5, 38.0, 36.8, 36.5, 34.8, 32. 8,a構型。31.5, 31.2, 27.6, 26.9, 21.4,21.1, 20.6,19.2,在得到葡萄糖三氯亞胺酯糖基給體后,對薯蕷皂16. 6, 16.5, 13. 2; HRESI- MS Calcd for Co5 H2OsNa苷元12為轉化為膽甾烷型苷元13的反應進(jìn)行了研究。(M+Na)+: 1 117. 4920; found: 1 117. 489 1。文獻[12-13]報道,在0°C條件下,以及三氟化硼乙醚1.2.4甲基Funlioside B2的合成將化合物 15 .(BF3●OEtz)的促進(jìn)下,12能以以84%的產(chǎn)率得到化(30.0 mg, 0. 027 mmol)溶于1.0 mL甲醇、1.0 mL合物13。但令人失望的是,在該條件下只以28%的產(chǎn)THF和125 μL蒸餾水的混合溶液中,加入LiOH●率得到化合物13,同時(shí)也以47%的產(chǎn)率得到副產(chǎn)物化H2O (10.2 mg, 0. 24 mmol, 9.0 equiv. ),在50°C條合物14。通過(guò)對反應溫度的優(yōu)化,作者發(fā)現當控制反件下反應。攪拌12 h后,TLC (CH2Cl2 : CH3OH =應溫度為- 5°C,乙酸酐和三氟化硼乙醚為10當量與78: 1)顯示反應完全。加人Dowex-50(H+ )樹(shù)脂調pH當量時(shí),可以55%和27%的產(chǎn)率得到期望的化合物13為5~6,過(guò)濾、減壓蒸除溶劑,所得殘余物經(jīng)硅膠柱層和副產(chǎn)物14 (Scheme 2)。析(CH2Cl2 : CH3OH=10: 1)得到白色固體。在無(wú)水以三甲基硅基三氟甲磺酸酯為促進(jìn)劑,在5A分子甲醇中回流24h,得到白色固體甲基FunliosideB2篩存在條件下,葡萄糖三氯亞胺酯給體11和膽甾烷型(15.2 mg, 0. 026 mmol, 95%)。[aJH=-40.3° (c苷元13在二氯甲烷溶劑中進(jìn)行糖苷化反應,以83%的1.0, CH:OH);' H NMR (600 MHz, pyridine-ds) δ產(chǎn)率的立體 選擇性地得到1,2-反式的β-型糖苷15。在5.40(d,J=4.9 Hz,1H),4.85 (d,J=7.7 Hz,甲醇/水/四氫呋喃混合溶液中,用LiOH●H2O于1H), 4.58 (dd,J=11.6, 2.2 Hz, 1H), 4.47~4. 3950°C脫除15中的4個(gè)苯甲?;?個(gè)乙?;?將所得(m, 2H), 4.24 (m, 2H), 4.03 (t,J=8.3 Hz, 1H),產(chǎn)物在無(wú)水甲醇中回流24h,最終以95%的產(chǎn)率得到3.96(m,1H),3.85(m,1H),3.60(m,1H),3.26甲基Funlioside B (2)。文獻[14-17]報道,在氘代吡啶(s, 3H),2.62 (m, 2H),2.22~1.71 (m, 10H),中當呋甾皂苷的22位甲氧基為a構型時(shí),C2的化學(xué)位1.61~1.32 (m, 9H), 1.20 (d,J=6.6 Hz,3H),移為112. 4 ppm。得到的甲基Funlioside B (2),其Cn的1.05(s, 3H), 1.00 (d,J=6.6 Hz, 3H), 0.84 (s,化學(xué)位移為112.4 ppm,與文獻值- .致,因此22位甲氧3H).; I3C NMR (150 MHz, pyridined;) δ 141.7,基為 a構型。選用回流溫度條件下,脫除?;Wo基是120.8,112.4, 104.7, 81.0, 78.3, 78.2, 74. 9,由于15中16位乙?;^大的空間位阻,在較溫和的條71.4,71.0, 63.9, 62.6, 56.4, 50.1, 47.0,43. 2,件下(甲醇鈉/甲醇,室溫條件下攪拌)不能脫除。40.5,40.2, 39.5, 37.5, 36.7, 33.9, 32.3, 32. 0,31.9,31.4, 30.5, 27.9, 20.8,19.3, 16.9, 16. 0;~OR .HRESI-MS Calcd for C34 Hs O, Na (M + Na)+ :人Bye上>-0Ac631. 381 7; found: 631. 379 9。H0個(gè)13R=HAcO-diosgenin 1214 R-AcOHOBz11HoWOH→Bg0V s ,oR BzO-崗BzOCCl,D-葡萄糖-9R,-Bz" NH-10R,=H .Bzd h((a) BzCI, DMAP, pyridine, rt, 12h, 100%; (b) MeNH2- EtOH,HoBz1:THF, rt, 6h, 68%; (c) CClzCN, DBU, CH2Cl2, rt, 4h, 96%. )((a) Ac2O, BF3●OEt2, CH2Clz, -5°C, 55% for 13 and 27% for 14;Scheme 1 Reagents and conditions(b) TMSOTf, 5AMS, CH2Cz, rt, 5h. 83%; (c) i) 1iOH. H2O,2結果與討論CH2OH,THF, H2O, 50°C , 12h; i) CHsOH, relux, 24h, 95%. )中國煤化工tions首先是D葡萄糖三氯亞胺酯給體11的合成。將3結語(yǔ)MYHCNMH GD-葡萄糖溶解在無(wú)水吡啶溶液中,與苯甲酰氯反應得到全苯甲?;漠a(chǎn)物9,然后在甲胺醇溶液中選擇性的本文以易得的薯蕷皂苷元為原料,以6步反應.8中國海洋大學(xué)學(xué)報201 4年29%的總產(chǎn)率得到甲基Funlioside B (2)。在三氟化硼induction [J]. Bioorg Med Chem Lett, 2011. 21: 2075-2078.乙醚條件下,經(jīng)過(guò)一一步反應實(shí)現甾體皂苷螺旋甾烷型[9] Diab Y, loannou E, Roussis V. Desmettianosides A and B, bis-desmosidie furostanol saponins with molluscicidal activity from向膽甾烷型的轉化,大大的縮短了合成步驟,提高了合Yucca desmettiana[J]. Steroids, 2012, 77: 686-690.成的效率;在最后脫除保護基團的同時(shí),又實(shí)現了E環(huán)[10] Yokosuka A, Mimaki Y, Sashida Y. Steroidal and Pregnane Gly-的關(guān)環(huán),得到呋喃甾烷甾體皂苷。這些工作順利進(jìn)行cosides from the Rhizomes of Tacca chantrieri[J]. J Nat Prod,為合成結構更為復雜的三糖、四糖呋甾皂苷奠定了堅2002, 65: 1293-1298.實(shí)的實(shí)踐基礎,也為呋甾皂苷進(jìn)行更為廣泛深人的生11] Gauthier C, Legault J, Lebrun M, et al. Glycosidation of lupanetype triterpenoids as potent in vitro cytotoxic agents[J] Bioorg物活性與作用機制的研究提供了有利條件。Med Chem, 2006, 14: 6713-6725.參考文獻:[12] Fernendez Herrera M A, Sandoval-Ramirez J, Meza-ReyesS, etal. Side chain opening of steroidal sapogenins to form 22-oxochol-[1] Hostettmann K, Marston A. saponins[ M]. New York: Cambridgeestanic skeletons. An approach to analogues of the aglycone of theUnvercity Press, 1995.potent anticancer agent 0SW-1[J]. J Mex Chem Soc, 2009,53;[2] Victoria L, Sonia P, De Voss J J. NMR asgnment of the absolute126-130.configuration of C-25 in furostanol steroidal saponins[J]. Steroids,[13] Fernandez Herrera M A, Lopez Munoz H, Hernandez Vazquez J2012, 77; 602 -608.M V,et al. Synthesis of 26 hydroxy 22 -oxocholestanic frame-[3] Waller G R, Yamasaki K. Saponins used in Traditional and Mod-works from diosgenin and hecogenin and their in vitro antiprolifer-erm Medicine[M]. New York: Plenum Press, 1996.ative and apoptotic activity on human cervical cancer CaSki cells[4] Rao A V, Gurfinke! D M. Drug metabol[J]. Drug Interact, 2000,J]. Bioorg Med Chem, 2010, 18: 2474 2484.17: 211.[14] ZouK, WangJ z, Du M, et al. A pair of diasterecisomeric ster-[5] Zhao Y,Feng B, Ma B P. Biotransformation of Dichotomin byoidal sapunins f rom cytotoxic ext ract s of Tupistra chinensis rhi-pectinex BE XXL[J]. ChinJ Nat Med, 2009, 7(5): 381-389.zomes [J]. Chem Pharm Bull, 2006, 54: 1440- 1442.[6] Matsuda H, Pongpiriyaacha Y, Morikawa T, et al. Protective[15] Festa C, Zollo F, lorizzi M, et al. Novel Steroidal Componentseffects of steroid saponins from paris polyphylla var. yunnanensisfrom the Underground Parts of Ruscus aculeatus LJ]. Mole-on ethanol- or indormethacin-induced gastric mucosal lesions in rats:cules, 2012, 17: 14002-14014.structural requirement for activity and mode of action[J]. Bioorg[16] Diab Y, loannou E, Emamb A. et al. Desmetti anosides A andMed Chern Lett, 2003, 13: 1101-1106.B,bisdesmosidic furostanol saponins with molluscicidal activity[7] WangG H, Chem M,Huang N, et al. Methyl protodioscin infrom Yucca desmettiana[J] Steroids, 2012, 77: 686 690.duces G2/M cell cycle arrest and apoptosis in HepG2 liver cancer17] Yokosuka A, Jitsuno M, Yui S, et al. Steroidal Glycosides fromcell[J]. Cancer Lett, 2006, 241: 102-109.AgaWe utahensis and Their Cytotoxic Activity[J].J Nat Prod,[8] KimK H,Kim M A, Moon E, et al. Ro. Furostanol saponins2009, 72: 1399-1404.from the rthizomes of Dioscorea japonica and their efects on NGFThe Synthesis of Methy| Funlioside BLI Bao-Jie, WANG Peng, XIE Jiang Feng, WANG Yue-Jiao, SONG Tian-Jia, LI Ming(The Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of Chi-na, Qingdao 266003,China)Abstract: Methyl Funlioside B,a furostanol saponin , has been accomplished. The reaction of diosgeninwith Ac2O in the presence of BF3●OEtz led to 3, 16-di-O-acetyl-22oxo-chlora13 in a 55% yield. Underthe promotion of trimethylsilyl trifluoromethanesulfonic acid, compound 15 was synthesized by the cou-pling of 13 with glucopyranosyl tricholoracetimidate 11 in 83% yield. Final removal of protecting groupsof acty by LiOH●H2() in MeOH/H2O/THF followed by refluxing in anhydrous methanol providedmethyl funlioside B in 95% yield.Key words: methyl funlioside B; furostanol saponin; glycosidatior中國煤化工YHCNMHG責任編輯徐環(huán)

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