醚氨基及氨基酸的各种保护基及去保护方法大全Word文档下载推荐.docx

醚氨基及氨基酸的各种保护基及去保护方法大全Word文档下载推荐.docx

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Theresultingresidueispurifiedbyflashchromatography（SiO2）ifnecessary.

Removal

Theglycosideisdissolvedinmethanolandasolutionofsodiummethoxideinmethanol（0.1eqper-OAc）isaddeddropwiseat0°

. 

ThesolutioniswarmedtoroomtemperatureandstirredunderaninertatmosphereuntilcompletebyTLC（usuallywithinafewhours）. 

AmberlitecationicexchangeresinisthenaddedwithvigorousstirringuntilthepHofthemixtureisneutral. 

Themixtureisthenfilteredandconcentrated. 

Theresultingresidueispurifiedbyflashchromatography（SiO2）ifnecessary.

OR

TheGlycosideisdissolvedinmethanolandhydrazinehydrate（15eqper-OAc）isaddedintwoportionsover1.5hours. 

ThesolutionisstirredatroomtemperatureunderaninertatmosphereuntilcompletebyTLC（usually6hours）. 

Thesolutionisthenneutralizedwithglacialaceticacid. 

Themixtureisfilteredthroughceliteandconcentrated. 

References

J.Org.Chem.,1996,61,6442-6445.

"

SyntheticMethodsforCarbohydrates"

Lemieux,Ch6,pg.90-115.

J.Chem.Soc.,PerkinTrans.1,1996,985-993.

Bz-（benzoate）ester

Toasolutionoftheglycosidedissolvedindrypyridine（0.3M）,benzoylchloride（4eqper-OH）isaddedatroomtemperatureunderaninertatmosphereandstirreduntilcompletebyTLC（usually16h）. 

Methanolisaddedandthesolutionwasconcentratedinvacuo. 

TheresiduewasdissolvedinDCMandwashedwithwater,saturatedcoppersulfate,andbrine. 

Theorganiclayerisdriedandconcentratedinvacuo. 

TheglycosideisdissolvedinMeOHandasolutionofNaOH（2.5eqper-OH）inMeOHisaddedslowly. 

ThemixtureisstirredatroomtemperatureunderaninertatmospheretillcompletebyTLC（usually1h）andthenconcentratedinvacuo. 

Theresidueisdissolvedinethylacetateandtheorganicsolutioniswashedtwicewithwater,dried（sodiumsulfate）,andconcentratedinvacuo. 

Tetrahedron,1970,26,803-812.

Carb.Res.,1993,244,237-246.

Piv-（pivaloate）ester

StandardProcedure

Theglycosideisdissolvedinpyridine:

DCM2:

1andcooledto-20°

PivCl（1.2eqper-OH）isthenaddeddropwiseunderaninertatmosphereandtheresultisstirredat0°

untilcompletebyTLC（usually8h）. 

ThemixtureisthendilutedwithDCMandextractedwith5%HCltwiceandoncewithwater. 

Theorganiclayeristhendried（sodiumsulfate）andconcentratedinvacuo. 

TheglycosideisdissolvedinMeOH,andasolutionofsodiummethoxideinmethanol（10eqper-OH）isaddeddropwiseatroomtemperatureunderaninertatmosphereandstirreduntilthereactioniscompletebyTLC（usually24h）. 

AqueousHCl（10%）isaddedtothesolutionuntilneutralandtheresultingmixtureisconcentratedinvacuo. 

Theresidueispurifiedbyflashchromatography（SiO2）ifnecessary.

Tet.Asym.2000,295-303.

J.Am.Chem.Soc.1990,112,3693-3695.

Lev-（levulinate）ester

Toasolutionoftheglycosideindrypyridineatroomtemperatureunderaninertatmosphere,levulinicanhydride（2eq）isaddeddropwise. 

ThereactionwasstirreduntilcompletebyTLC（usually24h）andicewaterisadded. 

Themixtureisextractedwithchloroformandthentheorganiclayerisbackextractedwithbrine,dried（sodiumsulfate）,andconcentratedinvacuo. 

Theglycosideisdissolvedinpyridineandhydrazinehydrate（1Minpyridine:

aceticacid3:

2）isaddedatroomtemperatureunderaninertatmosphere. 

AfteradditionofhydrazineissufficienttoconsumestartingmaterialcompletelybyTLC（usuallyafewminutes）,pentane-2,4-dioneisaddedwithcoolingtoquenchthereaction. 

Themixtureisdilutedwithchloroformandextractedoncewithwaterandoncewithbrine. 

Theorganiclayerisdried（sodiumsulfate）andconcentratedinvacuo. 

JACS,1975,97,1614-1615.

Tet.Lett.,1976,52,4875-4878.

[Benzyl][Trityl][PMP][Allyl][pMB][BacktoCarb.Synthesis]

Bn-（benzyl）ether

Toasolutionofsodiumhydride（1.3eqper-OH）inDMF,theglycoside（dissolvedinDMF）isaddeddropwiseat0°

underaninertatmosphere. 

Themixtureisstirredfor30minutesat0°

andbenzylbromide（1.3eqper-OH）isaddeddropwise. 

*Note-acatalyticamountofTBAIorcrownethercanbeadded. 

ThereactionisstirredatroomtemperatureuntilcompletebyTLC（usually16h）andmethanolisaddedslowlytoquenchthereaction. 

Thesolutionisthendilutedwithchloroformandwater,extracted3timeswithwaterandoncewithbrine. 

ToasolutionoftheglycosideinDCM,benzyltrichloroacetimidate（2eqper-OH）isaddeddropwise（asasolutionincyclohexane-seethirdreference）withTfOH（catalytic->

1mol%）. 

TheresultisstirredatroomtemperatureunderinertatmosphereuntilcompletebyTLC（usuallyovernight）. 

SaturatedaqueoussodiumbicarbonateisaddedandthemixtureisdilutedwithDCM. 

Theorganiclayerisextractedoncewithwater,oncewithbrine,dried（sodiumsulfate）,andconcentratedinvacuo. 

Theglycosideisdissolvedin1:

1MeOH:

tBuOHandpalladiumhydroxide（0.1eq）isaddedatroomtemperature. 

Ahydrogenatmosphereisadded（balloonpressure）andthereactionisstirreduntilcompletebyTLC（usually16h）. 

*Note-catalyticglacialacidicacidmaybeaddedifthereactionisn'

tcomplete. 

J.Org.Chem.,1979,44,3442.

J.Am.Chem.Soc.,1971,93,1746.

Tr-（triphenylmethyl）ortritylether

Toasolutionoftheglycoside,tritylchloride（1.1eqforprimaryoversecondary,1.5eqforeach-OHotherwise）,andtriethylamine（1.5eqforprimaryoversecondary,2eqforeach-OHotherwise）stirringinDMFunderaninertatmosphereatroomtemperature,DMAP（0.05eq）isadded. 

ThereactionisstirreduntilcompletebyTLC（usuallyovernight）andthenpouredintoice-water. 

Themixtureisextractedwithchloroformandtheorganiclayeriswashedwithsaturatedaqueousammoniumchlorideandwater,dried（sodiumsulfate）,andconcentratedinvacuo. 

Theglycosideisdissolvedinethanoland5%palladiumoncharcoalisaddedunderahydrogenatmosphere. 

ThereactionisstirreduntilcompletebyTLC（usuallyovernight）andfiltered. 

Thesolutionisconcentratedandtheresidueispurifiedbyflashchromatography（SiO2）ifnecessary.

Tet.Lett.,1979,2,95-98.

JOC,1978,18,2877-2881.

pMB-（para-methoxybenzyl）ether

andpara-methoxybenzylbromide（1.3eqper-OH）isaddeddropwise. 

TheglycosideisdissolvedinDCM/H2O20:

1andDDQ（upto10eq）isaddedatroomtemperatureunderaninertatmosphere. 

ThereactionisstirreduntilcompletebyTLC（usually24h,mayrequireheat）anddilutedwithDCM. 

Thesolutionisextractedwithsaturatedaqueoussodiumbicarbonate,dried（sodiumsulfate）,andconcentratedinvacuo. 

Productcanthenbepurifiedbycolumnchromatographyifnecessary. 

JACS,1992,114,2524-2536.

JACS,1996,118,9265-9270.

Allyl-（allyl）ether

andallybromide（1.3eqper-OH）isaddeddropwise. 

Thereactionisstirredatroomtemperature