Improved preparation of β-D-ManNAc-(1→4)-D-Glc and β-D-TalNAc-(1→4)-D-Glc disaccharides and evaluation of their activating properties on the natural killer cells NKR-P1 and CD69 receptors

DOI: 10.1080/07328300802030845

Source and publish data:

Journal of Carbohydrate Chemistry p. 156 - 171 (2008)

Update date:2022-09-26

Topics: Data Analysis Purification and characterization Publication and Further Research

Authors:

Attolino, Emanuele

Bonaccorsi, Filippo

Catelani, Giorgio

D'Andrea, Felicia

K?enek, Karel

Bezou?ka, Karel

K?en, Vladimir

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1080/07328300802030845

The synthetic access of either β-d-ManNAc-(1→4)-d-Glc (5) is β-d-TalNAc-(1→4)-d-Glc (6) disaccharides has been effectively improved with respect to previous syntheses (J. Carbohydr. Chem. 2000, 19, 79-91 and 2004, 23, 179-190), optimizing the preparation

Full text of DOI:10.1080/07328300802030845

This article was downloaded by: [University of Nebraska, Lincoln]

On: 28 December 2014, At: 20:24

Publisher: Taylor & Francis

Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office:

Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Journal of Carbohydrate Chemistry

Publication details, including instructions for authors and subscription

information:

http://ww w .tandfonline.com/loi/lcar20

Improved Preparation of

β‐d‐ManNAc‐(1→4)‐d‐Glc and

β‐d‐TalNAc‐(1→4)‐d‐Glc Disaccharides and

Evaluation of Their Activating Properties

on the Natural Killer Cells NKR‐P1 and CD69

Receptors

Emanuele Attolino ^a, Filippo Bonaccorsi ^a, Giorgio Catelani ^a, Felicia

D'Andrea ^a, Karel Křenek ^b, Karel Bezouška ^{b c}& Vladimir Křen ^b

^aDipartimento di Chimica Bioorganica e Biofarmacia , Università di Pisa ,

Pisa , Italy

^bInstitute of Microbiology , Academy of Sciences of the Czech Republic,

Laboratory of Biotransformation , Czech Republic

^cFaculty of Science, Department of Biochemistry , Charles University

Prague , Czech Republic

Published online: 12 Jun 2008.

To cite this article: Emanuele Attolino , Filippo Bonaccorsi , Giorgio Catelani , Felicia D'Andrea , Karel

Křenek , Karel Bezouška & Vladimir Křen (2008) Improved Preparation of β‐d‐ManNAc‐(1→4)‐d‐Glc

and β‐d‐TalNAc‐(1→4)‐d‐Glc Disaccharides and Evaluation of Their Activating Properties on the Natural

Killer Cells NKR‐P1 and CD69 Receptors , Journal of Carbohydrate Chemistry, 27:3, 156-171, DOI:

10.1080/07328300802030845

To link to this article: http://dx.doi.org/10.1080/07328300802030845

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”)

contained in the publications on our platform. However, Taylor & Francis, our agents, and our

licensors make no representations or warranties whatsoever as to the accuracy, completeness, or

suitability for any purpose of the Content. Any opinions and views expressed in this publication

are the opinions and views of the authors, and are not the views of or endorsed by Taylor &

Francis. The accuracy of the Content should not be relied upon and should be independently

verified with primary sources of information. Taylor and Francis shall not be liable for any

losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities

whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or

arising out of the use of the Content.

This article may be used for research, teaching, and private study purposes. Any substantial

or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or

distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use

can be found at http://www.tandfonline.com/page/terms-and-conditions

RETRACTED RETRACTED RETRACTED RETRACTED

Journal of Carbohydrate Chemistry, 27:156–171, 2008

RETRACTED RETRACTED RETRACTED RETRACTED

ISSN: 0732-8303 print 1532-2327 online

DOI: 10.1080/07328300802030845

RETRACTED RETRACTED RETRACTED RETRACTED

Improved Preparation of

RETRACTED RETRACTED RETRACTED RETRACTED

b-^D-ManNAc-(1!4)-D-Glc

RETRACTED RETRACTED RETRACTED RETRACTED

^RETa^RAn^CTd^EDb^R-^E^D^T-^RT^Aa^CTl^EN^DA^REc^T-^R(^A1^C!^TED4^R)^E-^TD^RA-G^CTl^Ec^D

RETRACTED RETRACTED RETRACTED RETRACTED

Disaccharides and

RETRACTED RETRACTED RETRACTED RETRACTED

Evaluation of Their

RETRACTED RETRACTED RETRACTED RETRACTED

Activating Properties on the

RETRACTED RETRACTED RETRACTED RETRACTED

Natural Killer Cells NKR-P1

RETRACTED RETRACTED RETRACTED RETRACTED

and CD69 Receptors

RETRACTED RETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRAC₁TED RETRACTED

RET^E_FR_e^mA_li^a_cCⁿ_ia^uT_D^eE^l_’^eD_A^A_nR_d^tt_rE^o_e^lT_aⁱⁿ_,R^o₁^,A_Ka^FCⁱ_r^l_eⁱT^p_l^pE_K^o_ˇrD_e^B_nR^o_eⁿ_kE^a_,₂T^c_KR^c_a^oA_re^rsC_l^i,_BT_e^GE_zoⁱD^o_u^rg_ˇsR_k^io_aE_,^C₂T_,3^aR^tA^elaCⁿT^i,ED

RET_aR_nA_dC_VT_laE_dD_imR_{ir K}E_ˇrT_enRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

Dipartimento di Chimica Bioorganica e Biofarmacia, Universita di Pisa, Pisa, Italy

²Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of

RET_BR_ioA_traC_nsT_foE_rmD_atioR_n,E_CzT_ecR_hA_ReC_puT_bliE_cD RETRACTED RETRACTED

³Faculty of Science, Department of Biochemistry, Charles University Prague, Czech

RET_RR_epA_ubC_licTED RETRACTED RETRACTED RETRACTED

RET_TR_hA_{e s}C_yntT_heE_tiD_{c ac}R_cesE_{s o}T_{f e}R_itA_herC_bT_-D-E_MD_anNR_AcE_-(1T_!R₄₎A_-D-C_GlT_{c (5}E₎D_{is b}R_-D-E_TaT_lNR_AcA_-(1C_!T_4)-E_D-D_Glc

(6) disaccharides has been effectively improved with respect to previous syntheses

RETRACTED RETRACTED RETRACTED RETRACTED

(J. Carbohydr. Chem. 2000, 19, 79–91 and 2004, 23, 179–190), optimizing the prep-

RETRACTED RETRACTED RETRACTED RETRACTED

aration of suitably protected 4-O-(2-acetamido-2-deoxy-3,4-O-isopropylidene-b-D-talo-

RET^pR^yrA^anC^osyT^l)E^-2,D^3:5,R^6-dE^i-OT^-R^isoA^proC^pyT^lidE^enD^e-aR^ldeE^hyT^doR^-DA^-glC^ucoT^seE^dD^imeR^thE^ylT^acR^etaA^{l d}C^erT^ivaE^tiD^ves

obtained by complete stereoselective LiAlH₄reduction of new 2⁰-oximino precursors

RETRACTED RETRACTED RETRACTED RETRACTED

Received November 19, 2007; accepted February 8, 2008.

RETRACTED RETRACTED RETRACTED RETRACTED

Part 22 of the series “Chemical Valorization of Milk-Derived Carbohydrates.” For Part

RETRACTED RETRACTED RETRACTED RETRACTED

21 see Ref. 34.

RET^A_BR^d_ioA^d_fa^re_rC^s_m^sT_a^c_c^o_iE_a^rr_,D^e_U^sp_n^oR_iⁿ_v^d_eE_r^e_sⁿT_i^c_ta^e_`R^t_d^oA_i^G_PCⁱ_i^o_saT^rg_,ⁱE_V^o_iD^C_a^a_B^teR_o^l_n^aE_aⁿ_nⁱT^,_n^D_oR_,^ip₃A^a₃^r_-^t_ICⁱ_-^m₅₆T^e₁ⁿ₂E^t₆^oD_,^d_Pⁱ_iR_s^C_a^h_,E^im_ItT_a^ic_lR^a_y^B_aA_n^io_dC^or_V^gT_l^a_aⁿE_dⁱ_i^c_mD^a_i^e_r

Kren, Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory

RETRACTED RETRACTED RETRACTED RETRACTED

of Biotransformation, Videnska 1083, CZ 142 20 Praha 4, Czech Republic. E-mail:

giocate@farm.unipi.it or kren@biomed.cas.cz

RETRACTED RETRACTED RETRACTED RETRACTED

156

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

157

RETRACTED RETRACTED RETRACTED RETRACTED

derived from lactose. The afﬁnity of the disaccharides 5 and 6 toward the natural killer

RETRACTED RETRACTED RETRACTED RETRACTED

^ceR^{ll N}E^KT^R-R^P1A^anC^dT^CDE⁶D^{9 re}R^cepE^toT^rsR^haA^{s b}C^eeTⁿE^evD^aluaR^teE^{d a}T^ndR^dA^iscC^usT^sedE^.D RETRACTED

Keywords b-D-ManNac-(1!4)-D-Glc, b-D-TalNAc-(1!4)-D-Glc, NK cells, NKR-P1

RETRACTED RETRACTED RETRACTED RETRACTED

receptor, 2-Oximino-b-D-lyxo-hexopyranosides, Reductions

RETRACTED RETRACTED RETRACTED RETRACTED

INTRODUCTION

RETRACTED RETRACTED RETRACTED RETRACTED

2-Amino-2-deoxyhexoses constitute an important class of monosaccharides

RETRACTED RETRACTED RETRACTED RETRACTED

present as N-acetamido derivatives in several kinds of naturally occurring

_biR_oloE_giT_caR_llyA_aC_ctiT_veE_cD_ompR_oE_unT_dsR_._[1A_]_TC_heT_mE_oD_{st i}R_mE_poT_rtR_anA_{t m}C_eT_mE_beD_{rs o}R_fE_thT_{e f}R_amA_ilC_yTED

are certainly N-acetyl-^D-glucosamine (1) and its C-4 epimer, N-acetyl-D-galac-

RETRACTED RETRACTED RETRACTED RETRACTED

^toR^saE^miT^neR⁽²A^),C^boT^thE^dD^isplR^ayEⁱⁿT^gR^anA^eqC^uaT^toE^riD^allyR^oE^rieT^ntR^edA^aC^cetT^amEⁱD^{do g}R^roE^upT^aR^{t C}A^-2C^.TED

In particular, they are constituent of different types of glycoconjugates (glyco-

[2]

RETRACTED RETRACTED RETRACTED RETRACTED

lipids, lypopolysaccharides, and glycoproteins),

glycosaminoglycans

(heparin, dermatan, chondroitin, and hyaluronic acid),^[3]and blood group

RETRACTED RETRACTED RETRACTED RETRACTED

determinants.^[4]

_inR_voE_lviT_ngR_cA_ellC_ulT_arE_reD_cogR_niE_tioT_nR_._[5A

]

^{Furthermore, the}C^{y p}T^laE^yD^sigR^niﬁE^caTⁿR^{t r}A^oleC^sTⁱⁿE^seD^verR^alE^pT^roR^cesA^seC^sTED

Much less distributed in nature are the two

analog aminosugars carrying an axially disposed C-2 acetamido group:

RETRACTED RETRACTED RETRACTED RETRACTED

^NR^-acE^etT^ylR^-D-A^mC^anT^noE^saD^miR^neE⁽T³⁾R^aA^ndC^NT^-aE^ceD^tylR^-D-E^taT^loR^saA^miC^neT⁽E⁴⁾D^{. In}R^pE^aT^rtiR^cuA^laC^r,TED

N-acetyl-^D-mannosamine is a constituent of the capsular polysaccharide

[6,7]

_reR_peE_atT_inR_{g u}A_nC_itT_ofE_soD_meR_pE_atT_hoR_geA_nsCTED RETRACTED RETRACTED

and of the natural spacer unit linking

[8]

^teR^ichE^oiT^cR^acA^idsC^tT^oE^thD^{e p}R^epE^tidT^ogR^lyA^caCⁿT^chE^aiD^{n in}R^sE^omT^eR^GA^raC^mT^-pE^osD^itivR^{e b}E^aT^cteR^riA^a.CTED

N-acetyl-D-talosamine has been recognized only as a minor constituent of

RETRACTED RETRACTED RETRACTED RETRACTED

[9]

ovine and bovine cartilage.

RETRACTED RETRACTED RETRACTED RETRACTED

R^AEⁿTⁱR^ntA^ereC^stTⁱⁿE^gD^comR^mE^onT^bR^ioA^logC^icT^alE^roD^leR^ofE^thT^eR^foA^urC^hT^exE^osD^amRⁱⁿE^esT¹R^–4A^aC^sTED

agonists of the major activating receptors of rat natural killer cells, NKR-P1,

was established from our previous studies.^[10,11]In this contest, a systematic

RETRACTED RETRACTED RETRACTED RETRACTED

study of the structural requirements of the recombinant soluble dimeric form

[11]

_ofR_NE_KT_R-R_P1A_foC_rT_itsE_oD_ptiR_maE_lT_caR_rbA_ohC_ydT_raE_teD_ligR_anE_dsT_wR_aA_{s m}C_aT_deE_,D_sR_hoE_wT_ingR_tA_haC_tTED

(a) the afﬁnity of N-acetyl-^D-hexosamines is in the order ManNAc . GalNAc

RETRACTED RETRACTED RETRACTED RETRACTED

^.R^GE^lcNT^AR^cA^..C^TT^aE^lND^Ac;R^(bE^{) t}T^heR^oA^rieC^ntT^atE^ioD^{n of}R^thE^eT^anR^omA^eC^ricT^sE^ubD^stitR^ueEⁿT^{t i}R^{s v}A^erC^yTED

important, showing, in all cases, an increase of the afﬁnity of about two

RETRACTED RETRACTED RETRACTED RETRACTED

orders of magnitude when it is ﬁxed as b-pyranoside bond; and (c) the preferred

ⁱⁿR^terE^glT^ycR^osA^idiC^cT^coEⁿⁿD^ectR^ioE^n,TⁱⁿR^tA^heC^cT^asE^eD^ofR^diE^-T^anR^dA^olC^igoT^saE^ccD^harR^idE^esT^,R^isA^thC^eTED

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁵⁸ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

b-(1!4) one. It could be noted that an apparent lack of structurally related

RETRACTED RETRACTED RETRACTED RETRACTED

regularity is present in the afﬁnity for the NKR-P1 receptor of the four hex-

RETRACTED RETRACTED RETRACTED RETRACTED

osamines 1–4. In fact, while in the C(2)-NHAc equatorial couple GlcNAc/

RETRACTED RETRACTED RETRACTED RETRACTED

GalNAc (1/2) the most active by one order of magnitude is the second one

RET^dR^isA^plaC^yiT^ngE^aD^{n a}R^xE^ialT^CR^-4A^hC^ydT^roE^xyD^{l gr}R^ouE^pT^{, i}RⁿA^theC^CT^-4E^eD^pimR^eE^ricT^cR^ouA^pleC^oT^fE^C(D^2)-

NHAc axially oriented ManNAc/TalNAc (3/4) is the ﬁrst one having the C-4

RETRACTED RETRACTED RETRACTED RETRACTED

hydroxyl group equatorially disposed that is by far the most active by three

orders of magnitude. This apparently anomalous behavior was explained con-

RETRACTED RETRACTED RETRACTED RETRACTED

RET^s_fR_o^id_rA_m^er_sCⁱⁿ_[1^g₂T_]^t_aE^h_n^aD_d^t_s^TR_u^a_p^lE^N_po^AT_s^c_iR_n⁽_g⁴A⁾_thⁱCⁿ_atT^a_o^qE_n^u_lD_y^eo_p^u_yR^s_ra^sE^o_n^lT_o^u_s^tR_e^io_fAⁿ_o^s_rmC^o_s^cT^c_a^uE_r^r_e^sD_s^m_ui^aR_tⁱ_aⁿE_b^ly_lT_eⁱ_fRⁿ_orA^it_b^s_iC_n^fu_dT^r_in^aE_gⁿ_.^oD_[1^s₁^e_]

In order to demonstrate this hypothesis, it was necessary to test some

RETRACTED RETRACTED RETRACTED RETRACTED

RET^MR^aA^nNC^AT^cE^anD^dR^TaE^lNT^AR^{c b}A^-pC^yrT^anE^osD^ideR^s,E^foT^rR^whA^icC^hT^syE^ntD^hesR^isE^thT^rR^ouA^ghC^coT^mE^mD^on

glycosidation methods, however, is difﬁcult because of the general problems

[13,14]

RET_eR_ncA_ouC_ntT_erE_edD_inR_tE_heT_cR_onA_stC_ruT_ctiE_onD_ofR_bE_-1T_,2R_-ciA_{s h}C_eT_xoE_saD_minR_eE_pyT_rR_anA_osiC_deT_s.ED

Recently in this context new stereoselective methods have been proposed for

RETRACTED RETRACTED RETRACTED RETRACTED

the preparation of b-1,2-cis hexosamine glycosides based on stereoselective

RETRACTED RETRACTED RETRACTED RETRACTED

manipulations of b-D-galactopyranoside. Starting from lactose, the two title

disaccharides (5 and 6) have been prepared avoiding the difﬁcult glycosidation

RETRACTED RETRACTED RETRACTED RETRACTED

[15,16]

RET^sR^teA^psC^.TED RETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

We present here the results concerning the optimization of our previous

RETRACTED RETRACTED RETRACTED RETRACTED

RET^aR^pA^proC^acT^heE^sD^{to b}R^otE^hT^diR^saA^cchC^aT^ridE^esD⁵R^anE^dT^6,R^deA^ﬁnCⁱⁿT^gE^anD^efR^fecE^tiT^veR^imA^pC^rovT^eE^meD^nt

on the preparation of some intermediates. The evaluation of 5 and 6 and of

[17]

RET_tR_heA_bC_-mT_etE_hyD_{l D}R_-taE_loT_saR_mA_inoC_mT_oE_noD_sacR_chE_arT_idR_{e 7}ACTED RETRACTED

as activators of two natural

killer cell receptors is also presented and discussed.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^RR^EA^SUC^LT^TSE^AD^NR^DE^DT^ISR^CA^UC^SST^IOE^ND RETRACTED RETRACTED

Our previous syntheses of 5^[15]and 6^[16]

RETRACTED RETRACTED RETR^wA^eC^reT^bE^asD^edR^onE^tT^heR^pA^reC^paT^raE^tiD^on,

respectively, of protected talosamine intermediates 12 and 14 obtained by

RET_sR_teA_reC_oseT_leE_ctD_iveR_hyE_dT_ridR_eA_reC_duT_ctE_ionD_ofR₆E_-OT_-tR_riA_tylC_-2T_-oE_ximD_inR_oE_prT_ecR_urA_sorC_sT₍₁E₁₎D_in

RET^tR^urAⁿC^prT^epE^arD^edR^froE^mT^tR^heA^trC^iaT^ceE^toD^nidR^{e 8}E^,T^diR^reA^ctlC^{y o}T^bE^taD^inedRⁱEⁿT^goR^odA^yC^ielT^dE^frD^om

lactose.^[18]However, when we considered the repreparation of 5 and 6, it

RETRACTED RETRACTED RETRACTED RETRACTED

appeared evident that the major drawback of our approach was in the use of

the trityl group for the temporary protection of OH-6⁰. The modest yield

RETRACTED RETRACTED RETRACTED RETRACTED

[18]

RET⁽_pR⁴_r⁵_oA^%_blC⁾_em^rT^e_,^pE_f^o_u^rD_r^t_t^e_h^dR_erE_coT_mR_plA_icaC_teT_dE_byD_theR_cE_haT_nR_geA_ofC_thT_eE_pD_roteR_ctE_ionT_fR_roA_mC_thT_eE₆₀_-D_O-

for the preparation of 10 by tritylation of 8 was the ﬁrst

[15]

RET_tR_riA_tylC_dT_erE_ivaD_tivR_eE₁₂T_{, t}R_oA_thC_{e a}T_ciE_d-D_staR_bleE_bT_enR_zyA_{l o}C_nT_eE₍₁₄D_{, S}R_chE_.T₁₎R_neA_edC_edTED

RET^tR^heA^syCⁿT^thE^esD^{is o}R^{f t}E^heT^bR^-DA^-MC^anT^NE^AcD^-coR^ntE^ainTⁱⁿR^gA^diC^sacT^chE^aD^rideR⁵E^.TRACTED

for

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

159

RETRACTED RETRACTED RETRACTED RETRACTED

_SR_chE_emT_eR₁ACTED RETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

R^WE^eT^cR^onA^siC^deT^reE^dD^{a p}R^roE^mT^isiR^ngA^aC^lteT^rnE^aD^tiveR^uE^siT^ngR^aA^sC^stT^arE^tinD^{g m}R^aE^teT^riaR^lA^thC^eTED

poliacetonated derivative 9, obtained in good yield directly from lactose.^[18]

[19]

RETRACTED RETRACTED RETRACTED RETRACTED

Recently compound 9 has been transformed in nearly quantitative yield

ⁱⁿR^toE^thT^eR^{2 -}A^ulC^{o d}T^erE^ivD^ativR^eE¹⁵T⁽R^ScA^h.C²⁾T^saE^vD^ingR^thE^eT^{6 -}R^OA^-mC^ethT^oE^xyD^isopR^roE^pyT^lR^(MA^IPC⁾TED

as a useful temporary protecting group. The MIP group proved to be stable

[20]

_alR_soE_uT_ndR_erA_tC_heT_oE_xiD_maR_tioE_nT_coR_ndA_itC_ionTE_prD_opoR_seE_dT_byR_TA_suC_daTE_anD_{d c}R_owE_oT_rkR_erA_sCTED

(NH₂OH HCl and Na₂CO₃in MeOH), if the base was added before the hydro-

RETRACTED RETRACTED RETRACTED RETRACTED

xylamino hydrochloride reactant. In fact, 6⁰-O-protected 2⁰-oximino derivative

RETRACTED RETRACTED RETRACTED RETRACTED

16 (Sch. 2) was obtained in an excellent 96% yield as the sole (E) diastereo-

isomer, because of the kinetic control operating in the basic reaction conditions.

RETRACTED RETRACTED RETRACTED RETRACTED

The selective removal of the MIP group (10:1 MeOH-H₂0 þ 0.5% AcOH)

RETRACTED RETRACTED RETRACTED RETRACTED

gave (E)-17 in nearly quantitative yield and, after standard benzylation, the

RETRACTED RETRACTED RETRACTED RETRACTED

6 -O-benzyl-O-benzyloximino derivative (E)-18 in 82% yield. Interestingly,

when the preparation of (E)-18 from 15 was performed without any puriﬁcation

RETRACTED RETRACTED RETRACTED RETRACTED

^ofRⁱⁿE^teT^rmR^eA^diaC^teT^sE^(ED^)-16R^aE^ndT⁽R^E)A^-1C^7,T^anE^oD^verR^alE^{l 8}T⁸R^%A^yiC^eldT^wE^aD^{s ob}R^taEⁱⁿT^edR^oA^veC^rTED

three steps.

RETRACTED RETRACTED RETRACTED RETRACTED

Scheme 2: Reagents and conditions. i: NH₂OH HCl, Na₂CO₃(16,96% yield); ii: NH₂OBn HCl,

RETRACTED RETRACTED RETRACTED RETRACTED

Na₂CO₃(19,94% yield); iii: MeOH-H₂0 10:1 þ 0.5% AcOH( 96% yield); iv: KOH, BnBr, THF, (82%

yield); v: LiAlH₄, Et₂O then Ac₂O, MeOH; vi: 80%aq AcOH, 808C(98%).

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁶⁰ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

The oximino to acetamido group transformation was performed through

RETRACTED RETRACTED RETRACTED RETRACTED

RET^c_lR_a^la_tA_i^s_o^s_nⁱC^ca_wT^l_i^m_tE_h^aDⁿ_Aⁱ_c^pR^u_O^lE^at_iT_n^ioRⁿ_M^sA_e^b_O^yC_H^rT_.^ed_TE^u_h^cD_e^tio_hⁿR_yd^wE_rⁱ_iT^t_d^h_eR^L_rAⁱ_e^A_d^lC_u^H_c⁴T_tiⁱ_oEⁿ_nD^E_w^t²_aR^O_sE^f_p^o_eT^l_r^lo_fR_o^w_r^e_mA^d_eC^b_d^yT_o^a_nE^ce_tD^t_h^y_e^-

RET_oR_xiA_miC_noT_dE_erD_ivaR_tivE_esT₁R_6–A₁₉C_tT_oE_chD_eckR_thE_eT_roR_leA_ofC_thT_eE_prD_oteR_ctE_ionT_pR_atA_teC_rnT_onE_tD_he

RET^rR^edA^ucC^tioTⁿE^stD^ereR^osE^eleT^ctR^ivA^ityC^.TED RETRACTED RETRACTED

As reported in Table 1, the diastereoselectivity of the reduction was

RET_sR_enA_siC_blyT_dE_epD_enR_deE_ntT_oR_nA_theC_pT_reE_seD_nceR_oE_fT_freR_eA_hyC_drT_oxE_ylD_grR_ouE_psT_oR_nA_thC_{e o}T_xiE_mD_es,

leading in the case of the fully protected O-benzyloxime 18 to the formation

RETRACTED RETRACTED RETRACTED RETRACTED

of the N-acetyl-^D-talosamino disaccharide 14, isolated as the sole diastereo-

RETRACTED RETRACTED RETRACTED RETRACTED

isomer in an excellent 85% yield. The disaccharide 5 was then obtained from

14 in 53% yield as previously described.^[15]This new synthesis of 5 from 9 in

RETRACTED RETRACTED RETRACTED RETRACTED

RET^aR³A^5%CT^ovE^erD^allR^yiE^elT^dR^isA^thC^usT^dE^eD^ﬁniR^telE^yT^mR^orA^{e e}C^fﬁT^ciE^enD^{t t}R^haEⁿT^thR^atA^pC^reT^vioE^uD^sly

RET^rR^epA^orC^teT^d,E^yiD^eldiR^ngE⁵TⁱⁿR^aAⁿC^ovT^erE^allD^poR^orE¹³T^%R^yA^ielC^{d s}T^taE^rtD^ingR^frE^omT⁸R^.ACTED

The prevalent formation of the talo derivatives 13 and 14 in all reductions

is evidently due to the intermolecular hydride attack mostly on the a-face of the

RETRACTED RETRACTED RETRACTED RETRACTED

RET^o_tR_h^x_eⁱA^m_sⁱC_yⁿ_n^oT_e^d_rE_g^o_i^uD_s^b_ti^l_c^eR_e^bE_f^o_fⁿ_eT_c^d_t^.R_s^T_oA^h_f^is_tC_h^s_eT^el_s^eE_t^c_e^tD_r^iv_ic^itR^y_hiEⁱ_n^s_dT^e_r^a_aR^s_nⁱA_c^ly_eC^e_e^x_xT^p_er^lE^a_teⁱDⁿ_d^ed_bR_y^taE_t^k_hTⁱ_e^ngR₃₀_,ⁱA₄ⁿ₀^t_-^oC_ac^a_eT^c_t^c_oE^o_n^uD_idⁿ_e^t

and of the stereoanomeric effect.^[21]The formation of the galacto diastereo-

RETRACTED RETRACTED RETRACTED RETRACTED

RETⁱR^soA^meC^rT²⁰EⁱⁿD^aR²²E^%T^yR^ielA^{d f}C^roT^mE¹⁷D^(hR^avEⁱⁿT^gR^boA^thC⁶T^-OE^HD^anR^{d N}E^-T^OHR^gA^roC^upT^sE^frD^ee)

and in 11% yield from 16 (having the 6⁰OH protected as MIP group and the

RETRACTED RETRACTED RETRACTED RETRACTED

oximino OH group free) can be reasonably attributed to an intramolecular

hydride transfer on the b-face of the C55N bond from intermediate alkoxyalu-

RETRACTED RETRACTED RETRACTED RETRACTED

RET^mRⁱA^niuC^mT^hE^ydD^ridR^{e s}E^peT^ciR^esA^.CTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

It was clear that the 6 -OMIP protecting group was removed during the

N-acetylation step because of the acid reaction conditions. Considering our

RETRACTED RETRACTED RETRACTED RETRACTED

Table 1: Stereoselectivity of the LiAlH reductions of oximino derivatives 16–19.

RETRACTED RETRACTED₄RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

Products

(isolated yield)

talo/galacto ratio

RET^CR^oA^mpC^oT^unE^dD RETRACTED RETRACTED RETRACTED

13 (62%) þ 20 (11%)

70/30

85/15

only talo

RET₁R₇ACTED RETRACTED RETRACTED RETRACTED

13 (53%) þ 20 (22%)

14 (85%)

RETRACTED RETRACTED RETRACTED RETRACTED

13 (84%)

RET¹R⁹ACTED RETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

161

RETRACTED RETRACTED RETRACTED RETRACTED

new achievements in the use of MIP temporary protection and that derivative

RETRACTED RETRACTED RETRACTED RETRACTED

13 can yield the completely deprotected talosamino disaccharide 6 through acid

RETRACTED RETRACTED RETRACTED RETRACTED

hydrolysis, avoiding, thus, the use of the trityl derivative 12, the formation of

RETRACTED RETRACTED RETRACTED RETRACTED

oximino derivative 19 was planned. Its synthesis was performed by treatment

^ofR¹⁵E^wT^itR^hA^O-C^beT^nzE^ylD^hydR^roE^xyT^laR^miA^neC^hT^ydE^roD^chlR^oriE^deT^aR^ndA^NC^a²T^CE^O³DⁱⁿR^ME^eOT^HR⁽⁹A^4%CTED

^y_foⁱR_l^e_l^l_o^dE_w^)._eT^C_d^oR_b^m_yA^p_N^oC^u_-aⁿT_c^d_eE_t¹_y⁹D_la^w_ti^aR_o^s_nE^t_.^h_AT^e_lⁿ_sR_o^tr_iA^a_nⁿC_t^s_h^f_i^oT_s^rmE_ca^eD_s^d_eⁱ_tⁿR_h¹_eE³_taT^t_l^h_oR^ro_d^uA_er^g_iC^h_va^tT^h_ti^e_vE_e^LDⁱ₁^A₃^lR^H_w⁴_aE^r_s^eT_i^d_sR^u_ol^c_aA^t_t^io_eCⁿ_dTED

as the sole diastereoisomer in a very good yield (84%). The completely de-

RETRACTED RETRACTED RETRACTED RETRACTED

protected disaccharide 6 was ﬁnally obtained from 13 in 98% yield through

_mR_ildE_aT_cidR_hA_ydC_roT_lyE_sisD_ofR₁₃E₍T₈₀R_%A_aqC_AT_cOE_HD_atR₈E₀₈T_C)R_{. I}A_{n t}C_hiT_sE_waD_{y t}R_heE_syT_nR_thA_esiC_sTED

of 6 was effectively improved from the reported^[16]31% overall yield starting

RETRACTED RETRACTED RETRACTED RETRACTED

from the polyacetonide 8 to the present 81% from the mixed acetonide 9.

RETRACTED RETRACTED RETRACTED RETRACTED

R^AE^sT^aR^mA^arC^giT^naE^{l o}D^bseR^rvE^atT^ioR^n,A^thC^eT^unE^exD^pecR^teE^dT⁴R^-OA^-isC^opT^roE^pyD^{l by}R^-pE^roT^duR^ctA²C¹TED

was obtained (7% isolated yield) during the reduction of (E)-18 in a run con-

ducted on a rather large scale, for which a long reaction time (8 d) was

RETRACTED RETRACTED RETRACTED RETRACTED

^reR^quE^irT^edR^foA^{r t}C^heT^coE^mD^pleR^teE^diT^saR^ppA^eaC^raT^ncE^{e o}D^{f th}R^eE^staT^rtRⁱⁿA^{g o}C^xiT^mE^e.D^{A si}R^mE^ilaT^{r r}R^edA^ucC^-TED

tive opening was previously observed in the analogous reduction of some b-L-

arabino acetonides with chloroalane^[22]but, to the best of our knowledge, to

RETRACTED RETRACTED RETRACTED RETRACTED

date it has not been observed using LiAlH₄. The presence in the reaction

RETRACTED RETRACTED RETRACTED RETRACTED

^mR^edE^iuT^mR^ofA^trC^acT^esE^ofD^AlHR³EⁱⁿT^eR^quA^iliC^brT^iuE^mD^witR^hE^LiT^AlR^HA⁴^cC^ouT^ldE^prD^oviR^deE^aTⁿR^exA^plaC^-TED

nation of this unprecedented result.

We have tested the potencies of the prepared oligosaccharides to inhibit the

RETRACTED RETRACTED RETRACTED RETRACTED

binding of two natural killer cell receptors, NKR-P1A and CD69, to their high-

RETRACTED RETRACTED RETRACTED RETRACTED

afﬁnity ligand, GlcNAc₂₃BSA neoglycoprotein (Table 2). While none of the newly

prepared compounds proved to be a good inhibitor for CD69, both ManNAc and

RETRACTED RETRACTED RETRACTED RETRACTED

the corresponding disaccharide display quite high afﬁnities for NKR-P1

_reR_cepE_toT_r,R_foA_{r w}C_hiT_chE_MD_anR_NAE_cT_isR_thA_{e h}C_igT_heE_stD_-afﬁR_niE_tyT_mR_onA_osaC_ccT_haE_riD_deR_ligE_anT_d.R_[11A_]CTED

RETRACTED RETRACTED RETRACTED RETRACTED

It is a rather intriguing question why just the b-ManNAc residue is one of

the strongest ligands for the NK-cells receptor. This residue can hardly be

RETRACTED RETRACTED RETRACTED RETRACTED

found on the surface of somatic cells or on the surface of transformed cells

[10]

RETRA_TC_hT_{e o}E_nD_{ly d}R_ocE_umT_eR_ntA_edC_ocT_cuE_rrD_encR_eE_ofT_thR_eA_MC_anT_NAE_cD_inR_mE_amT_mR_alA_{s i}C_sTED

(tumors).

its involvement in the sialic acid biosynthesis (5-neuraminic acid aldolase).^[23]

RETRACTED RETRACTED RETRACTED RETRACTED

Table 2: Afﬁnity of carbohydrate ligands to two NK-cell activation receptors,

RETRACTED RETRACTED RETRACTED RETRACTED

NKR-P1A (rat) and CD69 (human), expressed in the logarithmic scale (2logIC₅₀).

RETRACTED RETRACTED RETRACTED RETRACTED

Compound

NKR-P1

CD69

RETRACTED RETRACTED RETRACTED RETRACTED

TalNAc-b-OMe (7)

6.7

7.4

8.0

6.7

5.0

4.5

3.2

3.0

5.0

RETRACTED RETRACTED RETRACTED RETRACTED

TalNAc-b(1!4)Glc (6)

ManNAc-b(1!4)Glc (5)

RETRACTED RETRACTED RETRACTED RETRACTED

ManNAc (3)

GlcNAc (1)

RETRACTED RETRACTED RETRACTED RETRACTED

Data are average values from three independent experiments.

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁶²ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

Nevertheless, 2-acetamido-2-deoxy-D-mannopyranose (ManNAc) is a fre-

RETRACTED RETRACTED RETRACTED RETRACTED

quently occurring glycosyl residue in a number of bacterial capsular polysacchar-

RETRACTED RETRACTED RETRACTED RETRACTED

ides and lipopolysaccharides (e.g., Haemophilus inﬂuenzae and Streptococcus

[6,7,24,25]

RET_pR_nA_eumC_oT_niE_aeD_).RETRACTED RETRACTED RETRACTED

In the Gram-positive bacteria, such as Staphylococcus

RET^aR^uA^reuC^sT^HE^anD^{d B}R^aE^cilT^luR^sA^subC^tiT^lisE^{, t}D^heR^b-E^MT^anR^NAA^cC^reT^siE^duD^{e is}R^aE^cT^omR^poA^neC^ntT^oE^{f t}D^he

“linkage unit” attaching teichoic acids to the peptidoglycan.^[26]ManNAc is

RETRACTED RETRACTED RETRACTED RETRACTED

probably the strongest monosaccharidic ligand for the natural killer cell activat-

ing protein NKR-P1,^[11]and some ManNAc-containing saccharides (e.g., GlcNAc-

RETRACTED RETRACTED RETRACTED RETRACTED

[27]

RET^MR^aA^nNC^AT^c)E^wD^ereR^foE^unT^dR^toA^beC^stT^roE^ngD^imR^mE^unT^osR^timA^uC^lanT^tsE^.D RETRACTED

In the early stages of their evolution NK cells had as a major role defense

against bacterial invaders. At that stage detection of ManNAc was plausibly of

RETRACTED RETRACTED RETRACTED RETRACTED

RET^tR^heA^uC^tmT^osE^{t i}D^mpR^orE^taT^ncR^{e f}A^orC^thT^{e r}E^ecD^ognR^itiE^onT^oR^{f b}A^acC^terT^iaE^{l i}D^nfeR^ctiE^onT^aR^{s t}A^hisC^saT^cE^chD^ar-

ide was a clear-cut signal of the foreign-body invader. At present, pathogenicity

RETRACTED RETRACTED RETRACTED RETRACTED

of some bacterial strains occurring in their R-forms (pathogenic—contain

ManNAc) and S-forms (nonpathogenic—lower-content ManNAc) is related

RETRACTED RETRACTED RETRACTED RETRACTED

partly to the content of ManNAc. The b-ManNAc units have potent implication

RETRACTED RETRACTED RETRACTED RETRACTED

in the virulence and pathogenicity of some bacteria (e.g., S. pneumoniae 19F

and 19A).^[24,25]It was shown that the presence of mannosamine derivatives

RETRACTED RETRACTED RETRACTED RETRACTED

RET^cR^anA^cC^auT^seE^m_[D₂^o₈^d_–Rⁱ₃^ﬁ₀^c_]E^atT^ioRⁿA^ofC^thT^{e c}E^elD^{l w}R^allE^sT^ynR^thA^esC^isT^anE^dD^somR^eE^chT^aR^ngA^esCⁱⁿT^mE^uD^cin

RET^pR^roA^duC^ctT^ioE^n.D RETRACTED RETRACTED RETRACTED

At present the major role of the NK cells is the ﬁrst defense barrier against

tumors and virally infected cells. Thus, the ability to recognize activation by

RETRACTED RETRACTED RETRACTED RETRACTED

ManNAc seems to be an evolutionary rudiment; however, it could be efﬁciently

RETRACTED RETRACTED RETRACTED RETRACTED

used in the activation of these cells in the glycomimetics.

Another interesting feature of our disaccharide is its intrinsic stability in

RETRACTED RETRACTED RETRACTED RETRACTED

vivo. When another disaccharide with high activation potency toward NK

RETRACTED RETRACTED RETRACTED RETRACTED

cells is used [e.g. b-GalNAc-(1!4)-GlcNAc or b-GlcNAc-(1!4)-GlcNAc], it

RETRACTED RETRACTED RETRACTED RETRACTED

is very quickly decomposed by the exoglycosidase action of b-N-acetylhexosa-

RET^mRⁱA^nidC^asT^eE^orD^lysR^ozE^ymT^eR^pA^resC^enT^tEⁱⁿD^theR^bE^odT^{y ﬂ}R^uA^idsC^{. H}T^oE^wD^eveR^{r, r}E^esT^pR^ectA^ivC^{e e}T^nzE^yD^me

for the hydrolysis of the b-ManNAc moiety does not exist. This was tested

RETRACTED RETRACTED RETRACTED RETRACTED

also by respective chromogenic substrate 4-nitrophenyl 2-acetamido-2-

deoxy-b-D-mannopyranoside.^[31]Therefore, our structures are virtually

RETRACTED RETRACTED RETRACTED RETRACTED

RET^“R^glA^ycC^omT^imE^eD^ticsR^{” h}E^aT^viR^ngA^boC^thT^hE^igD^{h b}R^ioE^loT^gicR^alA^aC^ctiT^viE^tyD^anR^{d a}E^lsT^oR^hiA^ghC^stT^abE^ilD^ity

RETⁱRⁿA^vivC^o.TED RETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

RET^ER^XA^PC^ERT^IME^ED^NTR^AE^LTRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

RET^GR^eAⁿC^eT^raE^lD^MeR^thE^oT^dR^sACTED RETRACTED RETRACTED

Melting points were determined with a Koﬂer hot-stage apparatus and are

RET_uR_nA_corC_reT_ctE_edD_{. O}R_ptiE_caT_lR_rotA_atC_ionT_sE_wD_ereR_mE_eaT_suR_reA_dC_onT_aE_PD_erkR_in-E_ET_lmR_erA₂₄C₁T_poE_laD_ri-

RET^mR^eA^terC^aT^tE²⁰D⁺R²⁸E^C.T^NR^MA^RC^wT^erE^eD^recoR^rdE^edT^wR^itA^hC^aT^BrE^ukD^erR^AE^CT²⁰R⁰AⁱⁿC^strT^uE^meD^nt

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

163

RETRACTED RETRACTED RETRACTED RETRACTED

operating at 200.13 MHz (¹H) and 50.33 (¹³C) and with a Bruker Avance II 250

RETRACTED RETRACTED RETRACTED RETRACTED

spectrometer operating at 250.15 and 62.9 MHz for H and ¹³C, respectively,

RETRACTED RETRACTED RETRACTED RETRACTED

using Me₄Si as internal reference. Assignments were made, when possible,

RETRACTED RETRACTED RETRACTED RETRACTED

with the aid of DEPT, HETCOR, and COSY experiments. In the case of

^mR^ixtE^urT^esR^{, a}A^ssC^igT^nmE^eD^ntsR^wE^erT^{e m}R^aA^deC^bT^{y r}E^efD^errR^ingE^tT^oR^thA^{e d}C^iffT^erE^enD^cesRⁱⁿE^tT^heR^pA^eaC^kTED

ⁱⁿR^tenE^sT^itiR^es.A^AC^{ll r}T^eaE^ctD^ionR^{s w}E^eT^reR^foA^lloC^weT^dE^byD^TLR^CE^onT^KR^ieA^selC^geT^{l 6}E⁰D^F²⁵R⁴^wE^itT^hR^deA^tecC^-TED

tion by UV light and/or with ethanolic 10% phosphomolybdic or sulphuric acid,

and heating. Kieselgel 60 (E. Merck, 70–230 and 230–400 mesh, respectively)

RETRACTED RETRACTED RETRACTED RETRACTED

was used for column and ﬂash chromatography. Solvents were dried and

RETRACTED RETRACTED RETRACTED RETRACTED

puriﬁed by distillation according to standard procedure, and stored over 4 A

molecular sieves activated for at least 24 h at 2008C. MgSO was used as the

RETRACTED RETRACTED RETRACTED RETRACTED

drying agent for solutions.

RETRACTED RETRACTED RETRACTED RETRACTED

_4-R_O-E_[2T_-DR_eoA_xy-C_3,T_4-OE_-D_isopR_roE_pyT_liR_deA_neC_-6-T_O-E₍₁D_-meR_thE_oxT_y-R_1-mA_eC_thT_yleE_thD_yl)R_-2-E_oxT_imR_inA_o-CTED

R^bE^-DT^-lR^yxA^o-hC^exT^opE^yD^ranR^osyE^l]T^-2R^,3:A^5,6C^-dT^i-OE^-D^isopR^roE^pyT^liR^deA^neC^-alT^deE^hyD^doR^-D-E^glT^ucR^osA^eCTED

R_A^DEⁱ_sT^m_ol^eR_u^th_tA_i^y_o^l_nC^A_o^cT_f^e_t^tE_h^a_e^lD_c^[_r^(E_uR_d^)-_e¹E⁶_uT^]_loR_sidA_{e 1}C₅T₍₆E_.50D_g,R₁₁E_.2T_mR_mA_ol)C_{, ob}T_taE_inD_edR_froE_mT₉R_,_[1A_9]_iC_nTED

RETRACTED RETRACTED RETRACTED RETRACTED

MeOH (300 mL) was treated with solid Na₂CO₃(2.70 g, 25.4 mmol), stirred for

30 min at rt, and NH₂OH HCl (1.80 g, 25.8 mmol) was added. The reaction

RETRACTED RETRACTED RETRACTED RETRACTED

^mR^ixtE^urT^eR^wA^asC^hT^eaE^teD^{d t}R^oE^reT^ﬂuR^xA^anC^dT^sE^tirD^redR^uEⁿT^tilR^TA^LCCT^(3:E⁷D^hexR^anE^eT^-ER^tOA^AcC⁾TED

showed the complete disappearance of the starting material (4 h) and the for-

mation of a new product with R_f0.50. MeOH was removed at reduced

RETRACTED RETRACTED RETRACTED RETRACTED

pressure and the residue was partitioned between CH₂Cl₂(150 mL) and satd

RETRACTED RETRACTED RETRACTED RETRACTED

aq NaHCO₃(70 mL). The aqueous phase was extracted with CH₂Cl₂

(3 ꢀ 40 mL) and the organic phases were collected, dried, ﬁltered, and concen-

RETRACTED RETRACTED RETRACTED RETRACTED

^trR^ateE^dT^uR^ndA^erC^diT^mEⁱⁿD^isheR^dE^prT^esR^suA^reC^toT^gE^ivD^{e a}R^crE^udT^eR^reA^sidC^ueT⁽E^6.D^{35 g}R^{, 9}E⁶T^%R^yiA^eldC⁾TED

RETRACTED ^CR^NE^MT^RR⁾A^almC^oT^stE^exD^cluR^sivE^eT^lyR^byA^thC^eT^(EE⁾D^diasR^teE^reT^oiR^somA^eC^rTED

constituted (¹H and

of the title compound. Flash chromatography (2:3 hexane-EtOAc þ 0.1%

Et₃N) gave an analytical sample of (E)-16 as a clear syrup; R_f0.50 (3:7

RETRACTED RETRACTED RETRACTED RETRACTED

hexane-EtOAc); [a]_D–20.3 (c 1.1, CDCl₃); ¹H NMR (250 MHz, CD₃CN): d

RETRACTED RETRACTED RETRACTED RETRACTED

5.46 (dd, 1H, J_{1 ,3}¼ 0.7 Hz, J_{3 ,4}¼ 7.9 Hz, H-3⁰), 5.40 (d, 1H, H-1⁰), 4.46 (dd,

1H, J ¼ 6.2 Hz, J ¼ 7.6 Hz, H-2), 4.34 (d, 1H, H-1), 4.33 (dd, 1H,

RETRACTED RETRACTED RETRACTED RETRACTED

1,2

2,3

J_{4 ,5}¼ 1.3 Hz, H-4⁰), 4.17 (m, 1H, H-5), 4.06 (dd, 1H, J_3,4¼ 1.3 Hz, H-3), 4.02

_(dR_d,E_1HT_,R_JACTED RETRACTED RETRACTED RETRACTED

¼ 6.0 Hz, J_6a,6b¼ 8.4 Hz, H-6b), 3.97 (dd, 1H, J_5,6a¼ 6.2 Hz,

5,6b

_HR_-6aE_),T_3.R₈₇A_(dC_d,T₁E_H,D_JRETRACTED RETRACTED RETRACTED

¼ 6.2 Hz, H-4), 3.45 (m, 3H, H-5 , H-6 a, H6 b), 3.38,

4,5

^3.R³⁷E⁽²T^s,R^eA^acC^hT^3HE^,D^{2 ꢀ}R^OE^MT^e-R¹⁾A^{, 3}C^.1T⁵E^[s,D^3HR^,E^CT^(OR^MA^e)MC^eT²^],E¹D^.45R^{, 1}E^.3T^9,R¹A^.33C^,TED

1.31, 1.30, 1.29 [6s, each 3H, 3 ꢀ CMe₂),1.28 [s, 6H, C(OMe)Me₂]; ¹³C NMR

RETRACTED RETRACTED RETRACTED RETRACTED

(62.9 MHz, CD₃CN): d 151.8 (C-2⁰), 111.3, 110.6, 109.3 (3 ꢀ CMe₂), 106.3

(C-1), 100.9 [C(OMe)Me ], 100.6 (C-1⁰), 78.7 (C-3), 77.7, 77.6 (C-4, C-5), 75.9

RETRACTED RETRACTED RETRACTED RETRACTED

(C-2), 73.9 (C-4⁰), 72.0 (C-5⁰), 66.9 (C-6), 65.4 (C-3⁰), 60.6 (C-6⁰), 56.1, 53.7

₍₂R_ꢀE_OT_MR_eA_-1)C_{, 4}T_8.E₉D_[C(OR_ME_eT_)MR_eA_{], 2}C₇T_.6,E₂D_7.2,R₂₇E_.0T_{, 2}R₆A_.6,C₂₅T_.9E_{, 2}D_4.9R₍₃E_ꢀT_CR_MA_eC_),TED

RETRACTED RETRACTED RETRACTED RETRACTED

24.8, 24.7 [C(OMe)Me₂]. Anal. Calcd for C₂₇H₄₇NO₁₃: C, 54.63; H, 7.98; N,

^2.R³⁶E^{; f}T^ouR^ndA^CC^{, 5}T^4.E⁴⁵D^{; H}R^{, 8}E^.0T^3;R^N,A^2.C³⁸T^.ED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁶⁴ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

4-O-[2-Deoxy-3,4-O-isopropylidene-2-oximino-b-D-lyxo-hexopyranosyl]-2,3:5,6-

RETRACTED RETRACTED RETRACTED RETRACTED

di-O-isopropylidene-aldehydo-^D-glucose Dimethyl Acetal [(E)-17]

RETRACTED RETRACTED RETRACTED RETRACTED

A solution of (E)-16 (1.48 g, 2.50 mmol) in 10:1 MeOH-H₂O mixture (15 mL)

RET_wR_aA_{s t}C_reT_ateE_dD_witR_{h a}E_cT_etiR_{c a}A_ciC_{d (}T₇₀E_mD_{L) a}R_ndE_hT_eaR_teA_{d t}C_{o 5}T₀E_8CD_whR_ileE_sT_tirR_rinA_g.C_AT_fteE_rD_{2 h}

TLC analysis (3:7 hexane-EtOAc) revealed the complete disappearance of the

RETRACTED RETRACTED RETRACTED RETRACTED

starting material. The solution was then allowed to cool to rt and coevaporated

RETRACTED RETRACTED RETRACTED RETRACTED

with toluene (4 ꢀ 20 mL) under diminished pressure. Flash chromatography

puriﬁcation (2:3 hexane-EtOAc) of the crude residue (1.42 g) afforded pure

RETRACTED RETRACTED RETRACTED RETRACTED

RET⁽R^E)A^-1C^{7 (}T^1.E²⁵D^g,R⁹⁶E^%T^yiR^elA^d)C^asT^aE^wD^hitR^{e s}E^olT^idR^foA^amC^;T^R^fE⁰D^.32R⁽³E^:7T^heR^xaA^neC^-ET^tOE^AD^c);

[a]_D–2.0 (c 0.9, CHCl₃); ¹H NMR (250 MHz, CD₃CN): d 5.46 (d, 1H,

RETRACTED RETRACTED RETRACTED RETRACTED

J_{3 ,4}¼ 7.9 Hz, H-3 ), 5.31 (s, 1H, H-1 ), 4.63 (dd, 1H, J_1,2¼ 6.6 Hz, J_2,3

7.9 Hz, H-2), 4.37 (d, 1H, H-1), 4.26 (dd, 1H, J_{4 ,5}¼ 1.8 Hz, H-4⁰), 4.19

RETRACTED RETRACTED RETRACTED RETRACTED

RET⁽₁R^m_HA^,_,¹_JC^HT^{, H}E^-D^5),R^4.0E⁵T^(dR^d,A¹C^H,T^JE^5,6D^b^¼R⁶E^.0T^HR^z,A^J⁶C^a,6T^b^¼E⁸D^.6R^HzE^,T^H-R^6bA^),C^4.T⁰³E^(dD^d,

¼ 1.4 Hz, H-3), 3.99 (dd, 1H, J_5,6a¼ 6.3 Hz, H-6a), 3.90 (dd, 1H,

3,4

0 0

¼ 6.4 Hz, H-4), 3.66 (dd, 1H, J

¼ 8.1 Hz, J

¼ 11.6 Hz, H-6⁰b),

RETRACTED RETRACTED RETRACTED RETRACTED

4,5

5 ,6 b

6 a,6 b

3.55 (dd, 1H, J_{5 ,6 a}¼ 4.4 Hz, H-6⁰a), 3.39 (m, 1H, H-5⁰), 3.40, 3.38 (2s, each

RET₃R_HA_{, 2}C_ꢀT_OE_MD_e),R₃E_.10TR_(bsA_{, 1}C_HT_,E_OHD_-6R_),E_2.7T₀R_(bA_s,C_1HT_,E_ND_-OR_H)E_{, 1}T_.4R_7,A₁C_.43T_,E_1.D_39,

RET₁R_.3A_6,C_1.T₃₂E_,D_1.3R₀E_(6sT_,R_eaA_chC₃T_H,E₃D_ꢀR_CME_eT_);RACTED RETRACTED

C NMR (62.9 MHz, CD₃CN): d

151.4 (C-2⁰), 111.3, 110.2, 109.5 (3 ꢀ CMe₂), 107.2 (C-1), 100.9 (C-1⁰), 78.6

RETRACTED RETRACTED RETRACTED RETRACTED

RET⁽₍R^C_C-^-A₃³⁾₀₎^,C_,⁷T₆⁸₁^.2E_.8⁽D^C₍^-_C⁴R_-⁾₆^,₀E⁷_),⁷T^.₅⁶₆R⁽_.^C₉A_,^-5₅C^),₃T⁷_.8⁵E^.7₍₂D⁽_ꢀ^C-R_O²⁾_M^,E⁷_eT⁴_),^.R⁰₂⁽A₇^C_.4^-C⁵_,⁾T₂^,₇⁷E_.³₁^.D_,⁵₂^(C₇R_.^-₀⁴E_,^),T₂⁶₆R⁶_.8^.7_,A⁽₂^CC₅^-_.⁶T₉⁾_,^,E⁶₂D₄⁶_.^.₉⁰

(3 ꢀ CMe ). Anal. Calcd for C H NO : C, 52.97; H, 7.54; N, 2.69. Found C,

RETRACTED RETRACTED RETRACTED RETRACTED

23 39

RET⁵R^2.A⁹⁵C^{; H}T^,E^7.D^56;R^N,E²T^.65R^.ACTED RETRACTED RETRACTED

When a crude sample of (E)-16 obtained from 15 (12.5 g, 21.6 mmol) as

RET_rR_epA_orC_teT_dE_abD_ovR_eE_wT_asR_dA_irC_ectT_lyE_dD_e-OR_-mE_eT_toR_xyA_isoC_prT_opE_yD_lideR_naE_teT_d,R_pA_urC_eT_(EE_)-D₁₇

RET⁽R¹⁰A^.7C^g,T²⁰E^.5D^mR^moE^l)T^wR^asA^obC^taTⁱⁿE^edD^afR^terE^ﬂT^aR^shA^chC^roT^mE^atD^ogrR^apE^hyTⁱRⁿA^{a 9}C^5%TE^yiD^eld

RET^oR^veA^rC^twT^{o s}E^teD^psR^froE^mT¹R^5.ACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

RET⁴R^-OA^-[C^6-OT^-E^BeD^nzyR^l-2E^-OT^-bR^enA^zyC^loT^ximEⁱD^no-R^2-dE^eT^oxR^y-3A^,4C^-OT^-isE^opD^ropR^ylE^idT^enR^e-bA^-DC^-lyT^xoE^-D

hexopyranosyl]-2,3:5,6-di-O-isopropylidene-aldehydo-^D-glucose Dimethyl

Acetal [(E)-18]

RETRACTED RETRACTED RETRACTED RETRACTED

A solution of (E)-17 (2.00 g, 3.83 mmol) in THF þ 0.5% water (20 mL) was

RET_tR_reA_atC_edT_wE_itD_{h p}R_owE_dT_erR_edA_KC_OHTE₍₁D_.72R_g,E₃T_0.R_{7 m}A_mC_olT₎E_anD_{d 1}R_8-E_crT_owR_n-A₆C₍₅T_0.6E_mD_g,

RET₀R_.1A_{9 m}C_mT_oE_l),D_anR_{d t}E_heT_rR_esA_ultC_inT_gE_miD_xtuR_reE_wT_asR_vA_igoC_roT_usE_lyD_stiR_rreE_dT_aR_{t r}A_{t fo}C_rT₃₀E_mD_in

RET^aRⁿA^{d B}CⁿT^BrE⁽²D^.62R^gE^{, 1}T^5.R^{3 m}A^mC^olT^{) w}E^aD^{s ad}R^dE^edT^{. T}R^hA^{e r}C^eaT^ctiE^onD^mR^ixtE^urT^eR^waA^sC^stiT^rrE^edD^at

rt until TLC analysis (1:1 hexane-EtOAc) revealed the complete disappearance

RETRACTED RETRACTED RETRACTED RETRACTED

of the starting material (4 h, R_f0.15) and the formation of a major faster-

moving product (R 0.44). MeOH (20 mL) was added and the mixture was

RETRACTED RETRACTED RETRACTED RETRACTED

RET^fR^urA^thC^erT^stE^irD^redR^foE^rT¹⁰R^mAⁱⁿC^{. S}T^oE^lveD^ntsR^wE^eT^reR^reA^mC^ovT^edE^uD^ndeR^rE^reT^duR^ceA^dC^prT^esE^suD^re,

RET^t_aR^h_n^eA_d^r_tC^e_h^s_eⁱT^d_a^u_qE^e_pD^w_ha^a_sR^s_e^dE_w^is_aT^s_s^oR_f^lv_u^eA_r^d_thCⁱ_eⁿ_rT^C_exE^H_tr²D_a^C_c^l_t²R_e⁽_d³E_w⁰T_i^m_thR^L_C⁾A^a_HⁿC^d_CT_l^wE^a₍₄^sD^h_ꢀ^ed₃R₀^wE_m^itT^h_L)R^b_.^r_TⁱA_hⁿ_e^eC_c⁽_o¹T_l⁵_leE^m_ctD^L_e⁾_d^,

RET^oR^rgA^anC^icT^pE^haD^sesR^wE^erT^eR^coA^nceC^ntT^raE^teD^{d u}R^ndE^eT^{r d}R^imAⁱⁿC^isT^heE^dD^preR^ssE^urT^eR^anA^{d t}C^heT^cE^ruD^de

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

165

RETRACTED RETRACTED RETRACTED RETRACTED

residue puriﬁed by ﬂash chromatography (4:1 hexane-EtOAc) gave the title

RETRACTED RETRACTED RETRACTED RETRACTED

^coR^mpE^oT^unR^dA^(EC^)-1T⁸E⁽²D^.20R^g,E⁸T^2%R^yA^ieC^ld₁T^),E^asD^{a c}R^leE^arT^sR^yrA^upC^{; R}T^fE^0.D⁴⁴R^(1:E¹T^heR^xaA^neC^-TED

EtOAc); [a]_D220.6 (c 0.9, CHCl₃); H NMR (200 MHz, CDCl₃): d 7.38–7.26

RETRACTED RETRACTED RETRACTED RETRACTED

(m, 10H, Ar-H), 5.49 (d, 1H, J_{3 ,4}¼ 7.6 Hz, H-3 ), 5.48 (s, 1H, H-1 ), 5.19, 5.02

(AB system, 2H, J_A,B¼ 12.7 Hz, CH₂Ph), 4.63 (dd, 1H, J_1,2¼ 6.6 Hz,

RETRACTED RETRACTED RETRACTED RETRACTED

J_2,3¼ 6.8 Hz, H-2), 4.56, 4.49 (AB system, 2H, J_A,B¼ 11.9 Hz, CH₂Ph), 4.37

RETRACTED RETRACTED RETRACTED RETRACTED

(d, 1H, H-1), 4.31 (dd, 1H, J_{4 ,5}¼ 1.2 Hz, H-4 ), 4.24 (m, 1H, H-5), 4.15–3.93

(m, 4H, H-3, H-4, H-6a, H-6b), 3.68 (m, 1H, H-6⁰b), 3.62 (dd, 1H,

RETRACTED RETRACTED RETRACTED RETRACTED

J_{5 ,6 a}¼ 6.0 Hz, J_{6 a,6 b}¼ 9.5 Hz, H-6⁰a), 3.50 (m, 1H, H-5⁰), 3.35, 3.34 (2s,

RETRACTED RETRACTED RETRACTED RETRACTED

each 3H, 2 ꢀ OMe), 1.53, 1.42, 1.38, 1.37, 1.34, 1.33 (6s, each 3H, 3 ꢀ CMe₂);

¹³C NMR (50 MHz, CDCl ): d 150.3 (C-2⁰), 137.9, 137.0 (Ar-C), 128.2–127.5

RETRACTED RETRACTED RETRACTED RETRACTED

(Ar-CH), 110.2, 110.0, 108.2 (3 ꢀ CMe₂), 104.8 (C-1), 99.5 (C-1⁰), 78.0, 77.4,

RETRACTED RETRACTED RETRACTED RETRACTED

76.4, 76.3 (C-2, C-3, C-4, C-5), 76.8, 73.4 (2 ꢀ CH₂Ph), 73.1 (C-4⁰), 71.0 (C-5⁰),

RETRACTED RETRACTED RETRACTED RETRACTED

68.8 (C-6 ), 65.7 (C-6), 65.1 (C-3 ), 55.0, 52.0 (2 ꢀ OMe), 27.3, 26.6, 26.5, 26.1,

25.6, 24.7 (3 ꢀ CMe₂). Anal. Calcd for C₃₇H₅₁NO₁₂(701.82): C, 63.32; H, 7.32;

RETRACTED RETRACTED RETRACTED RETRACTED

N, 2.00. Found C, 63.35; H, 7.33; N, 1.96.

RETRACTED RETRACTED RETRACTED RETRACTED

When the preparation of (E)-18 was performed starting from 15 (13.1,

22.5 mmol), without any puriﬁcation of the intermediates (E)-16 and (E)-17,

RETRACTED RETRACTED RETRACTED RETRACTED

an overall 88% yield (13.9 g, 19.8 mmol) was obtained.

RETRACTED RETRACTED RETRACTED RETRACTED

^4-R^O-E^[2T^-OR^-bA^enzC^ylT^oxE^imD^inoR^-2E^-dT^eoR^xyA^-3,C^4-OT^-E^isoD^proR^pyE^liT^deR^neA^-6-C^O-T⁽¹E^-mD^ethR^oxE^y-T^1-RACTED

methylethyl)-b-D-lyxo-hexopyranosyl]-2,3:5,6-di-O-isopropylidene-

RETRACTED RETRACTED RETRACTED RETRACTED

aldehydo-^D-glucose Dimethyl Acetal [(E)-19]

Crude ketone 15 (3.50 g, 6.0 mmol) was treated with Na CO (1.45 g,

RETRACTED RETRACTED RETRACTED₂RETRACTED

13.7 mmol) and O-benzylhydroxylamine hydrochloride (1.92 g, 12.0) mmol) in

RETRACTED RETRACTED RETRACTED RETRACTED

^MR^eOE^HT⁽¹R⁵⁰A^mC^LT^{) a}E^sD^desR^crE^ibeT^dR^abA^ovC^eT^foE^{r t}D^heR^prE^epT^arR^atA^ionC^oT^{f (}E^ED^)-16R^{. A}E^ftT^erR^ﬂA^asC^hTED

chromatography of the reaction product (2:1 hexane-EtOAc), the title

compound (E)-19 was isolated (3.84 g, 94% yield) as a clear syrup having R_f

RETRACTED RETRACTED RETRACTED RETRACTED

0.49 (1:1 hexane-EtOAc); [a]_D217.9 (c 0.9, CHCl₃); ¹H NMR (250 MHz,

RETRACTED RETRACTED RETRACTED RETRACTED

CD₃CN): d 7.40–7.33 (m, 5H, Ar-H), 5.42 (s, 1H, H-1⁰), 5.40 (d, 1H,

¼ 7.8 Hz, H-3⁰), 5.18, 5.13 (AB system, 2H, J

¼ 12.4 Hz, CH Ph), 4.48

RETRACTED RETRACTED RETRACTED RETRACTED

3 ,4

A,B

^(dR^d,E^1HT^,R^JA^1,2C^¼T^6.E^{3 H}D^z,R^JE^2,3T^¼R^7.A^{6 H}C^zT^{, H}E^-D^2),R^4.E³⁴T⁽R^d,A^1HC^,T^HE^-1D^{), 4}R^.33E⁽T^ddR^,A^1HC^,TED

J_{4 ,5}¼ 1.3 Hz, H-4⁰), 4.15 (dt, 1H, J_5,6a¼ J_5,6b¼ 6.1 Hz, J_4,55.9 Hz, H-5),

_4.R₀₆E_(dT_dR_{, 1}A_HC_{, J}TED RETRACTED RETRACTED RETRACTED

¼ 1.4 Hz, H-3), 4.02 (dd, 1H, J_6a,6b¼ 8.6 Hz, H-6b), 3.93

3,4

^(dR^d,E^1HT^,R^HA^-6C^a),T³E^.8D^{8 (}R^ddE^{, 1}T^HR^,A^H-C^4),T³E^.5D^3–3R^.4E⁵T^(mR^,A^3HC^,T^HE^-5D^{, H}R^-6E^a,T^HR^-6A^bC^),TED

3.36, 3.35 (2s, each 3H, 2 ꢀ OMe-1), 3.14 [s, 3H, C(OMe)Me₂], 1.43, 1.37,

_1.R₃₀E_{, 1}T_.2R_9,A_1.C₂₈T_{, 1}E_.2D_{7 (6}R_s,E_eT_acR_hA_3HC_{, 3}T_ꢀE_CD_MeR₎E_{, 1}T_.3R₁A_[s,C_6HT_,E_CD_(OMR_eE_)MT_eR_];A_CCTED

NMR (62.9 MHz, CD CN): d 152.0 (C-2⁰), 138.4 (Ar-C), 129.4, 129.3, 129.0

RETRACTED RETRACTED RETRACTED RETRACTED

(Ar-CH), 111.4, 110.6, 109.2 (3 ꢀ CMe₂), 100.8 [C(OMe)Me₂], 106.3 (C-1),

RETRACTED RETRACTED RETRACTED RETRACTED

100.2 (C-1⁰), 78.7 (C-3), 77.8 (C-5), 77.6 (C-4), 77.5₀(CH₂Ph), 75.8 (C-2), 73.8

RETRACTED RETRACTED RETRACTED RETRACTED

(C-4 ), 72.0 (C-5 ), 66.8 (C-6), 66.3 (C-3 ), 60.5 (C-6 ), 56.0, 53.6 (2 ꢀ OMe-1),

48.8 [C(OMe)Me₂], 27.5, 27.2, 27.1, 26.7, 25.8, 25.0 (3 ꢀ CMe₂), 24.7, 24.6

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁶⁶ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

[C(OMe)Me₂]. Anal. Calcd for C₃₄H₅₃NO₁₃(683.80): C, 59.72; H, 7.81; N, 2.05.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^FR^oA^unC^{d C}T^,E⁵⁹D^.68R^{; H}E^,T^7.R⁸³A^{; N}C^{, 2}T^.0E^3.D RETRACTED RETRACTED

RET_GR_eA_neC_ralT_PE_roD_cedR_urE_eT_forR_thA_eC_ReT_duE_cD_tionR_oE_{f O}T_xR_imA_inoC_DT_erE_ivD_atiR_vesE₁T_6–R₁A₉CTED

A solution of the pertinent oximino derivative (16–19, 1.0 mmol) in dry

RETRACTED RETRACTED RETRACTED RETRACTED

RET^E_LR_i^t_A²A^O_lHC⁽¹T₍⁰₂E^m₇₅D^L_m⁾_gR^w_,^aE₇^s_.0T^s₀^lR^o_m^wA_m^ly_oC_l^a₎T^d_in^dE^e_d^dD_ry⁽¹R_E⁵_tE^m_OTⁱⁿ₍⁾R₁₀^aA^t_mC^r_L^t₎T_.^to_TE_h^aD_e^s_r^tR_eⁱ_a^rE_c^re_tiT^d_onR^su_mA^s_i^p_xC^e_tⁿ_uT^s_rⁱ_e^oEⁿ_wD_a^o_s^f

RET_hR_eaA_teC_dT_toE_rD_eﬂuR_xE_anT_dR_sA_tirC_redT_fE_orD_thR_eE_timT_eR_sA_peC_ciﬁT_edED_forR_evE_erT_yR_reA_acC_tioT_n.E_TD_he

RET^rR^eaA^ctC^ionT^mEⁱD^xtuR^resE^wT^eR^reA^quC^enT^chE^eD^{d by}R^tE^reT^atR^meA^ntC^{, i}TⁿE^orD^derR^{, w}E^itT^hR^H²A^OC⁽⁰T^.3E^mD^L),

RET¹_wR⁰_a^%A_sC_ﬁ^a_l^q_tT_e^N_rE_e^a_dD^OH_anR_d⁽⁰E^._r⁴_eT_p^mR_e^L_aA⁾_t^,_ed^aC_lⁿ_yT^d_wE^H_a²D_s^O_heR⁽_d^0.E_w³_i^mT_th^LR⁾_E^.A_t^TC^h_O^e_,T^w_aE_n^h_dD^ite_thR^g_e^rE^a_cⁿ_oT^u_ll^l_eR^a_c^r_tA_e^p_dC^re_e^cT_tⁱ_h^pE_e^it_r^aD_e^t_a^e_l

extracts were concentrated at reduced pressure. The crude residue was

RETRACTED RETRACTED RETRACTED RETRACTED

RET^d_oR_v^is_eA^s_r^o_nC^l_i^v_g^eT_h^d_tE_.ⁱⁿ_TD_h^M_e^eR^O_reE^H_acT_t⁽¹_iR_o²_nA^m_m^LC_i⁾_x^,T_t^t_u^rE_r^e_e^aD^t_w^ed_aR_s^aE^t_co^rT_e^t_vR^w_apⁱA^t_o^h_rC_a^A_te^cT_d²^OE_w⁽D_i²_th^mR_t^L_oE⁾_l^,_uT^a_eⁿ_nR^d_eA₍^le₄^fC^t_ꢀ^tT₁^o₀E^re_mD^a_L^ct₎

RET_uR_nA_deC_{r d}T_imE_inD_ishR_edE_pT_reR_ssA_ureC_aT_ndE_tD_{he c}R_ruE_deT_rR_esA_iduC_eT_suE_bjD_ecteR_dE_toT_ﬂR_asA_{h c}C_hrT_omE_aD_to-

RET^gR^raA^phC^icT^pE^urD^iﬁcaR^tiE^onT^.RACTED RETRACTED RETRACTED

RET_RR_eA_duC_ctiT_onE_oD_{f (E}R_)-1E₇TRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

A sample of (E)-17 (937 mg, 1.80 mmol) was submitted to reduction (8 h)

according to the general protocol described above, giving after ﬂash chromato-

RETRACTED RETRACTED RETRACTED RETRACTED

graphy (93:7 CH₂Cl₂-ⁱPrOH) the following products.

RETRACTED RETRACTED RETRACTED RETRACTED

4-O-[2-acetamido-2-deoxy-3,4-O-isopropylidene-b-D-talopyranosyl]-2,3:5,6-

RET_dR_i-A_O-C_isoT_prE_opD_yliR_deE_neT_-aR_ldA_ehyC_dT_o-DE_-gD_lucR_osE_{e D}T_iR_meA_thC_ylT_AcE_etD_{al (}R₁₃E₎TRACTED

White solid (522 mg, 53% yield); R 0.40 (93:7 CH Cl -ⁱPrOH); physical

RETRACTED RETRACTED RE_fTRACTED₂R₂ETRACTED

RET^pR^roA^peC^rtT^iesE^aD^ndR^NE^MT^RR^dA^ataC^aT^reEⁱD^denR^tiE^caT^{l t}R^oA^thC^osT^eE^ofD^{a p}R^reE^viT^ouR^slA^yC^deT^scE^ribD^ed

[16]

RET^sR^amA^pC^le.TED RETRACTED RETRACTED RETRACTED

4-O-[2-acetamido-2-deoxy-3,4-O-isopropylidene-b-D-galactopyranosyl]-

2,3:5,6-di-O-isopropylidene-aldehydo-^D-glucose Dimethyl Acetal (20)

RETRACTED RETRACTED RETRACTED RETRACTED

White solid foam (215 mg, 22% yield); R_f0.15 (93:7 CH₂Cl_2--ⁱPrOH);

RET_[R_a]A_þC₂T_2.2ED_{(c 0}R_.9E_5,T_CR_HA_ClC_);T₁E_HD_NMR_RET₍₂R₅₀A_MC_HzT_,E_CD_{D C}R_NE_):T_dR₆A_.50C₍T_d,E₁D_H,

¼ 9.0 Hz, NH), 4.56 (d, 1H, J

¼ 8.6 Hz, H-1⁰), 4.45 (dd, 1H,

RETRACTED RETRACTED RETRACTED RETRACTED

2 ,NH

1 ,2

RET^JR^1,A²^¼C⁶T^.7E^HD^{z, J}R^2,3E⁷T^.5R^HA^z,C^H-T²⁾E^{, 4}D^.34R^(dE^{, 1}T^HR^{, H}A^-1C^),T^4.E¹⁹D^(ddR^,E^1HT^,R^J²A^,3C^¼T^8.E^{3 H}D^z,

J_{3 ,4}¼ 5.2 Hz, H-3⁰), 4.17 (m, 1H, H-5), 4.04 (dd, 1H, J_{4 ,5}¼ 1.8 Hz, H-4⁰),

RET₄R_.0A_{0 (}C_ddT_,E_1HD_{, J}RETRACTED RETRACTED RETRACTED

¼ 1.4 Hz, H-3), 3.90 (m, 2H, H-6a, H-6b), 3.80 (m, 1H, H-4),

3,4

RET³R^.7A^{8 (}C^mT^{, 1}E^HD^{, H}R^-5E^),T^3.R⁶⁷A^(mC^{, 1}T^HE^,D^H-2R^),E^3.T⁵⁹R^(mA^,C^2HT^,E^HD^{-6 a}R^{, H}E^-6T^bR^),A^3.4C⁰T^(sE^{, 6}D^H,

2 ꢀ OMe), 1.87 (s, 3H, MeCO), 1.43, 1.39, 1.31, 1.30, 1.28, 1.26 (6s, each 3H,

RET₃R_ꢀA_CC_MT_eE_);D_CR_NE_MT_RR₍₆A_2.C_{9 M}T_HE_zD_{, C}R_DE_CNT₎R_{: d}A₁C₇₁T_.3E_(CD_O)R_{, 1}E₁₀T_.5R_{, 1}A₁₀C_.4T_{, 1}E₀D_8.9

(3 ꢀ CMe ), 107.8 (C-1), 102.1 (C-1⁰), 78.8 (C-3), 77.7, 77.6 (C-3⁰, C-5), 76.5,

RETRACTED RETRACTED RETRACTED RETRACTED

RET⁷R^6.A³C^(CT^-5E^,D^C-4R^),E⁷T^5.0R⁽A^C-C^2),T⁷E^4.D^{0 (}R^C-E^{4 )}T^,R⁶⁶A^.1C^(CT^-6E^),D⁶²R^.6E^(CT^-6R⁾A^{, 5}C^7.T^5,E⁵D^4.9

(2 ꢀ OMe), 55.5 (C-2⁰), 28.4, 27.5, 27.0, 26.8, 26.6, 25.1 (3 ꢀ CMe₂), 23.4

RET₍R_MA_eCC_O)T_.E_AnD_al.R_CE_alcT_dR_foA_rC_CT_HED_NORE_{: C}T_,R₅₄A_.6C_3;T_HE_{, 7}D_.89R_{; N}E_,T₂R_.55A_.C_FoT_unE_dD_C,

25 43

RET⁵R^4.A⁵⁵C^{; H}T^,E^7.D^85;R^N,E²T^.50R^.ACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

167

RETRACTED RETRACTED RETRACTED RETRACTED

Reduction of (E)-16

RETRACTED RETRACTED RETRACTED RETRACTED

R^TE^hT^eR^trA^eaC^tmT^enE^tD^ofR^(EE^)-1T⁶R⁽¹A^.0C^{0 g}T^,E^1.D⁶⁸R^mmE^oT^l)R^foA^rC^{8 h}T^,E^aD^ccorR^diE^ngT^tR^oA^thC^eTED

general protocol described above, gave after ﬂash chromatography (93:7

RETRACTED RETRACTED RETRACTED RETRACTED

CH₂Cl₂- PrOH) two pure samples of 13 (575 mg, 62% yield) and 20 (101 mg,

11% yield).

RETRACTED RETRACTED RETRACTED RETRACTED

Reduction of (E)-18

R_TE_rT_eaR_tmA_enC_{t o}T_fE_(ED_)-18R₍E₁₀T_.6R_g,A₁₅C_.1T_mE_mD_ol)R_forE₇T₂R_h,A_acC_coT_rdE_inD_{g to}R_thE_eT_geR_nA_eraC_lTED

^prR^otE^ocT^olR^dA^escC^riT^beE^dD^aboR^veE^,T^gaR^vA^eC^aftT^erE^ﬂD^asR^hE^chT^roR^mA^atoC^grT^apE^hD^{y (}R^3:7ET^heR^xaA^neC^-TED

EtOAc) 14 (8.21 g, 85% yield), having physical properties and NMR data iden-

RETRACTED RETRACTED RETRACTED RETRACTED

tical to those of the previously described compound.^[16]

R_IE_nT_aR_ruA_nC_coT_ndE_ucD_tedR_onE_aT_dR_ouA_blC_eT_amE_oD_untR_ofE_(ET₎R_-18A_{, t}C_heT_rE_edD_uctR_ionE_rT_atR_eA_waC_sTED

sensibly reduced requiring 8 d for the complete disappearance of the starting

RETRACTED RETRACTED RETRACTED RETRACTED

oxime. In this case, after chromatography, compound 14 was isolated in 74%

_yiR_eldE_aT_ndR_aA_sloC_weT_rmE_oD_vinR_gbE_yT_-prR_odA_ucC_twT_aE_{s i}D_solaR_teE_diT_n7R_%A_yiC_eldT_aE_ndD_ideR_ntE_iﬁT_edR_asA₂₁C_.TED

4-O-[2-acetamido-6-O-benzyl-2-deoxy-4-O-isopropyl-b-D-talopyranosyl]-

RETRACTED RETRACTED RETRACTED RETRACTED

^2,R^3:5E^,6T^-dR^i-OA^-iC^sopT^rE^opD^ylidR^enE^e-T^alR^deA^hyC^doT^-DE^-gD^lucoR^seE^DT^imR^etA^hyC^{l A}T^cE^etaD^{l (2}R¹⁾ETRACTED

_NR_MR^TE^hT^icR^{k s}A^yrC^upT^{; R}E^f_CD⁰_D^.1R⁴_C⁽_NE⁸⁵₎T_:^:1R^{5 C}A^HC²^CT^l²E^-MD^e²^CR^OE^);T^[aR^]^DA^¼C^–4T⁶E^(cD^1.0R^{, C}E^HT^CR^l³^);A^HCTED

(250 MHz,

d 7.25–7.15 (m, 5H, Ar-H), 6.61 (d, 1H,

J_{2 ,NH}¼ 9.7 Hz, NH), 4.69 (d, 1H, J_{1 ,2}¼ 1.7 Hz, H-1⁰), 4.50 (s, 2H, CH₂Ph),

RETRACTED RETRACTED RETRACTED RETRACTED

4.40 (m, 1H, H-2⁰), 4.37 (d, 1H, J_1,2¼ 6.2 Hz, H-1), 4.31 (dd, 1H, J_2,3¼ 6.7 Hz,

_HR_-2)E_,T_4.R₁₄A₍C_apT_p.E_sD_extR_etE_,T_1HR_,A_JCTED RETRACTED RETRACTED

¼ J_5,6b¼ 6.7 Hz, H-5), 3.98 (dd, 1H,

5,6a

¼ 1.5 Hz, H-3), 3.92 (m, 2H, H-6a, H-6b), 3.88 (dd, 1H, J ¼ 4.0 Hz, H-4),

RETRACTED RETRACTED RETRACTED RETRACTED

3,4

4,5

3.65 (m, 4H, H-4⁰, H-5⁰, H-6⁰a, H-6⁰b), 3.55 (m, 2H, H-3⁰, OCHMe₂), 3.31, 3.29

RETRACTED RETRACTED RETRACTED RETRACTED

(s, each 3H, 2 ꢀ OMe), 1.84 (s, 3H, MeCO), 1.38, 1.29, 1.28, 1.27 (4s, each 3H,

₂R_ꢀE_CMT_eR_),A_1.C₁₉T_{, 1}E_.1D_{0 (2}R_d,E_eT_acR_{h 3}A_HC_{, J}T_¼E₆D_{.1 H}R_zE_{, C}T_HR_MA_{e )}C_;TED RETRACTED

C NMR (62.9 MHz,

CD₃CN): d 170.8 (CO), 139.3 (Ar-C), 129.3–128.6 (Ar-CH), 110.9, 108.7

RETRACTED RETRACTED RETRACTED RETRACTED

(2 ꢀ CMe₂), 106.1 (C-1), 101.7 (C-1⁰), 78.8 (C-3), 78.4 (C-5), 76.6 (C-4), 76.3

RETRACTED RETRACTED RETRACTED RETRACTED

(C-2), 74.9, 74.7, 74.3 (C-4⁰, C-5⁰, OCHMe₂),), 73.8 (CH₂Ph), 69.3 (C-3⁰), 69.2

(C-6⁰), 66.1 (C-6), 55.9, 54.0 (2 ꢀ OMe), 53.8 (C-2⁰), 27.7, 27.0, 26.8, 25.8 (2 ꢀ

RETRACTED RETRACTED RETRACTED RETRACTED

CMe₂), 24.0, 23.0 (CHMe₂), 22.4 (MeCO). Anal. Calcd for C₃₂H₅₁NO₁₂: C,

RETRACTED RETRACTED RETRACTED RETRACTED

59.89; H 8.01; N, 2.18. Found C, 59.84; H, 7.99; N, 2.17.

RETRACTED RETRACTED RETRACTED RETRACTED

Reduction of (E)-19

RETRACTED RETRACTED RETRACTED RETRACTED

R^TE^rT^eaR^tmA^enC^{t o}T^fE^(ED^)-19R⁽E^1.8T³R^g,A^2.C⁶⁸T^mE^mD^ol)R^forE⁷T⁰R^h,A^acC^coT^rdEⁱⁿD^{g to}R^thE^eT^geRⁿA^eraC^lTED

protocol described above, gave after ﬂash chromatography (3:7 hexane-

RETRACTED RETRACTED RETRACTED RETRACTED

EtOAc) 13 (1.25 g, 84% yield), identical to the sample obtained above.

4-O-(2-acetamido-2-deoxy-b-D-talopyranosyl)-a,b-D-glucopyranose (6)

RETRACTED RETRACTED RETRACTED RETRACTED

R^AE^sT^olR^utA^ionC^oT^{f 1}E³D⁽³⁸R^{8 m}E^gT^{, 0}R^.7A^{0 m}C^mT^olE^{) i}D^{n 8}R^0%E^aT^qR^AcA^OHC⁽T¹⁵E^mD^L)R^waE^sT^waR^rmA^eC^dTED

at 808C and stirred for 5 h, when TLC analysis (1:1 CHCl₃-MeOH) revealed the

_coR_mpE_leT_teR_dA_isaC_ppT_eE_arD_ancR_eE_ofT_thR_eA_stC_artT_inE_gD_maR_teE_riaT_l.R_TA_heC_soT_luE_tiD_onR_waE_sT_coR_ncA_enC_-TED

^trR^ateE^dT^aR^{t d}A^imCⁱⁿT^isE^heD^{d p}R^reE^ssT^urR^eA^anC^dT^coE^evD^apoR^raE^teT^dR^wA^ithC^tT^oluE^eD^neR⁽⁴E^ꢀT¹⁵R^mA^LC^).TED

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁶⁸ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

The residue was triturated three times with CH₂Cl₂to give an amorphous

RETRACTED RETRACTED RETRACTED RETRACTED

[15]

RET^wR^hA^iteC^sT^oliE^dD⁽²⁶R^{3 m}E^gT^{, 9}R^8%A^yC^ieT^ldE^{) i}D^denR^ticE^alT⁽R^CA^NC^MT^RE^{) t}D^{o th}R^eE^saT^mR^pleA^pC^reT^vioE^uD^sly

RET^pR^reA^paC^reT^dE^byD^usR^.ETRACTED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

RET^BR^ioA^loC^gT^icE^aD^{l T}R^eE^stT^sRACTED RETRACTED RETRACTED

Compounds 1, 3, and 5–7 were tested for their afﬁnity toward two represen-

RET_tR_atA_iveC_NT_KE_-cD_ellR_acE_tivT_atR_ioA_nC_recT_epE_toD_rs,R_NE_KRT_-R_P1A_AC_anT_dE_CD_D69R_pE_roT_teR_inA_s.C_NKT_RE_-3D₉₁

protein, the major activation receptor of rat NK cells, was expressed and

RETRACTED RETRACTED RETRACTED RETRACTED

puriﬁed as described previously.^[10,11]CD69CWTY protein that contained the

RETRACTED RETRACTED RETRACTED RETRACTED

soluble ligand-binding domain of the earliest activation receptor of lymphocytes

and NK cells, CD69 antigen, was prepared as described earlier.^[32]The proteins

RETRACTED RETRACTED RETRACTED RETRACTED

RET^wR^eA^reC^puT^riE^ﬁeD^{d fr}R^omEⁱⁿT^cR^lusA^ionC^bT^odE^ieD^{s th}R^atE^wT^erR^{e d}A^issC^olT^veE^{d i}D^{n 6}R^ME^guT^aRⁿⁱA^dinC^-HT^CE^{l a}D^nd

100 mM DTT, and refolded by dropwise addition into a hundred times larger

RETRACTED RETRACTED RETRACTED RETRACTED

volume of 50 mM Tris-HCl buffer pH 8.5 containing 0.4M arginine, redox

buffer (10 mM cysteamine and 1 mM cystamine), 1 mM PMSF, 1 mM leupeptine,

RETRACTED RETRACTED RETRACTED RETRACTED

and 1 mM pepstatin. The folded protein was dialyzed against low salt buffer, and

RETRACTED RETRACTED RETRACTED RETRACTED

puriﬁed by a combination of ion exchange chromatography, reversed-phase sep-

aration, and gel ﬁltration as described previously.^[32]The identity and homogen-

RETRACTED RETRACTED RETRACTED RETRACTED

eity of the proteins was veriﬁed using SDS-PAGE under both reducing and

RETRACTED RETRACTED RETRACTED RETRACTED

nonreducing conditions, N-terminal sequencing (10 cycles of automated

RETRACTED RETRACTED RETRACTED RETRACTED

Edman degradation), and MALDI mass spectrometry, as described pre-

[32]

RET^vR^ioA^usC^ly.TE^MD^orR^eoE^veT^r,R^FoA^urC^ieT^rE^traD^nsfR^orE^mT^–iR^onA^cyC^clT^otE^ronD^reR^soE^naTⁿR^ceA^mC^asT^sE^spD^ec-

trometry was employed (APEX-Q, Bruker Daltonics, Bremen, Germany).^[33]

125

RET_TR_hA_{e p}C_roT_teE_inD_{s w}R_erE_eT_raR_dioA_laC_beT_ledE_wD_ithR_NE_aTRACTED RETRACTED

I using Iodogen (Pierce, Rockville,

IL, USA). Binding and inhibition assays were performed as described pre-

RETRACTED RETRACTED RETRACTED RETRACTED

viously.^[11]Brieﬂy, 96-well polyvinylchloride microplates (Titertek Immuno

RETRACTED RETRACTED RETRACTED RETRACTED

Assay-Plate, ICN Flow, Irvine, Scotland) were coated overnight at 48C with

RETRACTED RETRACTED RETRACTED RETRACTED

GlcNAc₂₃BSA (50 mL, Sigma) in PBS buffer (10 mM Tris-HCl, 150 mM NaCl,

RET¹R^mA^MC^CT^aCE^l²D^{, a}R^ndE¹T^mR^MA^NC^aNT³⁾E^{. P}D^latR^esE^wT^erR^eA^bloC^ckT^edE^wD^ithR¹E^%T^BR^SAAⁱⁿC^PT^BE^SD^for

2 h at 48C, incubated with the concentration of the radiolabeled protein corre-

RETRACTED RETRACTED RETRACTED RETRACTED

sponding to half of the saturating amount and various dilutions of the inhibitors

(total reaction volume 100 mL), washed three times with PBS, and drained. Scin-

RETRACTED RETRACTED RETRACTED RETRACTED

tillation solution (100 mL) was added, and the radioactivity in the individual

RETRACTED RETRACTED RETRACTED RETRACTED

wells was counted by b-counting (Microbeta, Wallac, Turku, Finland). All exper-

RETRACTED RETRACTED RETRACTED RETRACTED

iments were performed in duplicates and the inhibition degree was calculated

RET^wR^itA^hC^regT^aE^rdD^toR^theE^wT^eR^llsA^coC^ntT^ainEⁱⁿD^{g n}R^oEⁱⁿT^hibR^itA^or.CTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

RET^AR^CA^KC^NT^OE^WD^LER^DE^GT^MR^ENA^TC^STED RETRACTED RETRACTED

RETRACTED RETRACTED RETRACTED RETRACTED

This work was supported by the Ministero dell’Universita e della Ricerca

RET⁽R^MA^IUC^R,T^RE^omD^e,R^ItE^alT^y)RⁱⁿA^thC^eT^frE^amD^eR^ofE^thT^eR^COA^FC^INTⁿE^aD^tionR^alE^pT^roR^grA^amC^aT^ndE^tD^he

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

169

RETRACTED RETRACTED RETRACTED RETRACTED

Grant No. IAA400200503 from the Grant Agency of AVCR and COST D34

RETRACTED RETRACTED RETRACTED RETRACTED

(MSMT OC 136 and LC06010) are gratefully acknowledged.

RETRACTED RETRACTED RETRACTED RETRACTED

REFERENCES

RETRACTED RETRACTED RETRACTED RETRACTED

[1] Horton, D.; Wander, J.D. Amino sugars. In Carbohydrates. Chemistry and Bio-

RETRACTED RETRACTED RETRACTED RETRACTED

chemistry; Pigman, W. and Horton, D., Eds.; Academic Press: New York, 1980;

Vol. IB, 643–760.

RETRACTED RETRACTED RETRACTED RETRACTED

[2] Dwek, R.A. Glycobiology: toward understanding the function of sugars. Chem. Rev.

RETRACTED RETRACTED RETRACTED RETRACTED

1996, 96, 683–720.

RETRACTED RETRACTED RETRACTED RETRACTED

[3] Casu, B. Structure and biological activity of heparin. Adv. Carbohydr. Chem.

Biochem. 1985, 43, 51–134.

RETRACTED RETRACTED RETRACTED RETRACTED

RE^bio

, 3

^{[4] Varki, A. Biolo}E^{gical roles of oligosaccharides: all of the theories are correct. Glyco-}

RETRACTED RETRACTED RETRACTED

, 9

7–1

[5] Feizi, T. Carbohydrate differentiation antigens Trends. Biochem. Sci. 1981, 6,

RETRACTED RETRACTED RETRACTED RETRACTED

333–335.

RETRACTED RETRACTED RETRACTED RETRACTED

[6] Jennings, H.J. Capsular polysaccharides as human vaccines. Adv. Carbohydr.

Chem. Biochem. 1983, 41, 155–208.

RETRACTED RETRACTED RETRACTED RETRACTED

[7] Pozsgay, V. Oligosaccharide-protein conjugates as vaccine candidates against

RETRACTED RETRACTED RETRACTED RETRACTED

bacteria. Adv. Carbohydr. Chem. Biochem. 2001, 56, 153–199.

[8] Yoneyama, T.; Koike, Y.; Arakawa, H.; Yokoyama, K.; Sasaki, Y.; Kawamura, T.;

RETRACTED RETRACTED RETRACTED RETRACTED

Araki, Y.; Ito, E.; Takao, S. Distribution of mannosamine and mannosaminuronic

RETRACTED RETRACTED RETRACTED RETRACTED

acid among cell-walls of bacillus species. J. Bacteriol. 1982, 149, 15–21.

[9] Crumpton, M.J. Separation of talosamine from other 2-amino hexoses. Nature

RETRACTED RETRACTED RETRACTED RETRACTED

1957, 180, 605–606.

RETRACTED RETRACTED RETRACTED RETRACTED

[10] Bezouska, K.; Vlahas, G.; Horvath, O.; Jinochova, G.; Fiserova, A.; Giorda, R.;

Chambers, W.H.; Feizi, T.; Popsısil, M. Rat natural-killer-cell antigen, NKR-P1,

RETRACTED RETRACTED RETRACTED RETRACTED

related to C-type animal lectins is a carbohydrate-binding protein. J. Biol. Chem.

1994, 269, 16945–16952.

RETRACTED RETRACTED RETRACTED RETRACTED

[11] Krist, P.; Herkommerova-Rajnochova,

Rauvolfova, J.;

T.;

RETRACTED RETRACT_ˇED^ER^.;ETRACTED^SR^emE^eT^nuR^k,ACTED

Vavruskova, P.; Pavlıcek, J.; Bezouska, K.; Petrus, L.; Kren, V. Toward an

optimal oligosaccharide ligand for rat natural killer cell activation receptor NKR-

RETRACTED RETRACTED RETRACTED RETRACTED

P1. Biochem. Biophys. Res. Commun. 2001, 287, 11–20.

RETRACTED RETRACTED RETRACTED RETRACTED

[12] Angyal, S.J. The composition of reducing sugar in solution. Adv. Carbohydr. Chem.

Biochem. 1984, 42, 15–68.

RETRACTED RETRACTED RETRACTED RETRACTED

[13] Gridley, J.J.; Osborn, H.M.I. Recent advances in the construction of b-D-mannose

RETRACTED RETRACTED RETRACTED RETRACTED

and b-D-mannosamine linkages. J. Chem. Soc. Perkin Trans. 1 2000, 1471–1491.

[14] Bongat, A.F.G.; Demchenko, A.V. Recent trends in the synthesis of O-glycosides of

RETRACTED RETRACTED RETRACTED RETRACTED

2-amino-2-deoxysugars. Carbohydr. Res. 2007, 342, 374–406.

RETRACTED RETRACTED RETRACTED RETRACTED

[15] Attolino, E.; Catelani, G.; D’Andrea, F.; Nicolardi, M. A new preparation of the b-D-

ManNAcp-(1!4)-^D-Glc disaccharide from lactose through a highly stereoselective

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-Galp to b-D-ManNAcp transformation. J. Carbohydr. Chem. 2004, 23,

179–190.

RETRACTED RETRACTED RETRACTED RETRACTED

[16] Barili, P.L.; Berti, G.; Catelani, G.; D’Andrea, F.; Puccioni, L. Stereoselective syn-

RETRACTED RETRACTED RETRACTED RETRACTED

thesis of 4-O-(2-acetamido-2-deoxy-b-D-talopyranosyl)-D-glucose derivatives from

lactose. J. Carbohydr. Chem. 2000, 19, 79–91.

RETRACTED RETRACTED RETRACTED RETRACTED

¹R⁷⁰ET^ER^{. A}A^ttC^olinT^oE^etD^al.RETRACTED RETRACTED RETRACTED

[17] Barili, P.L.; Berti, G.; Catelani, G.; D’Andrea, F.; Di Bussolo, V. The conversion of

RETRACTED RETRACTED RETRACTED RETRACTED

RETRA

^D^a^-g^tT^a^a^{l.actopyranosides into 2-amino-2-deoxy-D-talopyranosyl derivatives: some new}

rbo

dr.

es.

, 2

, 17

–3

RACTED RETRACTED

[18] Barili, P.L.; Catelani, G.; D’Andrea, F.; De Rensis, F.; Falcini, P. Improved prep-

RETRACTED RETRACTED RETRACTED RETRACTED

aration of 2,3:5,6:3⁰,4⁰-tri-O-isopropylidenelactose dimethyl acetal and its 6⁰-O-(1-

methoxy-1-methylethyl) derivative. Carbohydr. Res. 1997, 298, 75–84.

RETRACTED RETRACTED RETRACTED RETRACTED

[19] Attolino, E.; Catelani, G.; D’Andrea, F. Regiospeciﬁc synthesis of 4-deoxy-^D-

RETRACTED RETRACTED RETRACTED RETRACTED

threo-hex-3-enopyranosides by simultaneous activation-elimination of the talo-

pyranoside axial OH-4 with the NaH/Im SO system: manifestation of the

RETRACTED RETRACTED RETR₂ACTED RETRACTED

stereoelectronic effect. Eur. J. Org. Chem. 2006, 5279–5292.

RETRACTED RETRACTED RETRACTED RETRACTED

[20] Tsuda, Y.; Okuno, Y.; Kanemitsu, K. Utilization of sugars in organic synthesis. XX.

Practical synthesis of nojirimycin. Heterocycles 1988, 27, 63–66.

RETRACTED RETRACTED RETRACTED RETRACTED

[21] Lichtenthaler, F.W.; Kaji, E.; Weprek, S. Disaccharide-derived 2-oxo- and 2-oxi-

RETRACTED RETRACTED RETRACTED RETRACTED

minoglycosyl bromides: novel, conveniently accessible building blocks for the

expedient construction of oligosaccharides with b-D-glucosamine, b-D-mannose,

RETRACTED RETRACTED RETRACTED RETRACTED

and b-D-mannosamine as constituent sugars. J. Org. Chem. 1985, 50,

RETRACTED RETRACTED RETRACTED RETRACTED

3505–3515.

[22] Liptak, A.; Szurmai, Z.; Olah, V.A.; Harngi, J.; Szabo, L.; Nanasi, P. Synthesis and

RETRACTED RETRACTED RETRACTED RETRACTED

hydrogenolysis of the methylene, ethylidene, isopropylidene, and diastereoiso-

RETRA_mC_erT_icE₁D_-phR_enE_yleT_thR_yliA_denC_eT_aE_cetD_alsR_ofE_bT_-LR_-aA_rabC_inT_o-E_aD_ndR_a-LE_-rT_haR_mA_nopC_yrT_anE_osD_ide

derivatives. Carbohydr. Res. 1985, 138, 1–15.

RETRACTED RETRACTED RETRACTED RETRACTED

ˇ ´

L.; Herkommerova-Rajnochova, E.;

T.; Kuzma, M.;

RET^[R²³A^{] H}C^uT^sakE^ovD^a,RETRACTED RETRACT^SE^eD^menR^ukE^,TRACTED

Rauvolfova, J.; Prikrylova, V.; Ettrich, R.; Plıhal, O.; Bezouska, K.; Kren, V. Enzy-

RETRA^mC^aT^ticE^diD^scriR^miE^naT^tioRⁿA^ofC^2-aT^ceE^taD^midR^o-2E^-dT^eoR^xyA^-D-C^maTⁿⁿE^opD^yraR^noE^seT^-coR^ntA^ainCⁱⁿT^{g d}E^isD^ac-

charides using b-N-acetylhexosaminidases. Adv. Synth. Catal. 2003, 345, 735–742.

RET_[R₂₄A_{] L}C_eeT_{, C}E_.JD_{.; B}R_anE_ksT_{, S}R_.DA_{.; L}C_{i, J}T_.PE_{. V}D_iruR_lenE_ceT_{, i}R_mmA_uC_nitT_y,E_anD_{d va}R_ccE_inT_{e r}R_elaA_teC_{d t}T_{o S}E_trD_ep-

tococcus pneumoniae. Crit. Rev. Microbiol. 1991, 18, 89–114.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^[R²⁵A^{] L}C^eeT^{, C}E^.-JD^{.; F}R^raE^seT^{r, B}R^.AA^{. T}C^heT^sE^truD^ctuR^resE^oT^{f t}R^heA^croC^ssT^-reE^acD^tiveR^tyE^peT^sR¹⁹A⁽¹⁹C^F)T^aE^ndD⁵⁷

(19A) pneumococcal capsular polysaccharides. J. Biol. Chem. 1980, 255,

6847–6853.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^[R²⁶A^{] Y}C^okT^oyE^amD^a,R^K.;E^MT^izR^ugA^uchC^i,T^HE^{.; A}D^rakR^i,E^Y.T^{; K}R^ayA^a,C^S.;T^ItE^o,D^{E. B}R^ioE^syT^ntR^heA^sisC^ofT^linE^kaD^ge

units for teichoic acids in Gram-positive bacteria: distribution of related enzymes

and their speciﬁcities for UDP-sugars and lipid-linked intermediates.

RETRACTED RETRACTED RETRACTED RETRACTED

J. Bacteriol. 1989, 171, 940–946.

RETRACTED RETRACTED RETRACTED RETRACTED

[27] Sedmera, P.; Prikrylova, V.; Bezouska, K.; Rajnochova, E.; Thiem, J.; Kren, V. Prep-

aration of ManNAc containing chitooligomers by isomerization and their binding to

RETRACTED RETRACTED RETRACTED RETRACTED

NKR-P1 protein. J. Carbohydr. Chem. 1998, 17, 1351–1357.

RET_[R₂₈A_{] N}C_aiT_k,E_R.D_{S.; D}R_aE_vidT_soR_n,A_E.AC_.;T_GoE_wD_da,R_D.CE_.T_DeR_veA_lopC_meT_ntE_alD_staR_ge-E_spT_ecR_iﬁcA_biC_osyT_ntE_heD_sis

of glycosylphosphatidylinositol anchors in intraerythrocytic Plasmodium falci-

RETRACTED RETRACTED RETRACTED RETRACTED

parum and its inhibition in a novel manner by mannosamine. J. Biol. Chem.

2000, 275, 24506–24511.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^[R²⁹A^{] K}C^epT^plE^erD^{, O.}R^T.;E^StT^ehR^linA^g,C^P.T^{; H}E^erD^rmaRⁿⁿE^,T^M.R^{; K}A^ayC^seT^r,E^H.D^{; Gr}R^unE^owT^,R^D.;A^RC^eutT^teE^r,D^W.;

Pawlita, M. Biosynthetic modulation of sialic acid-dependent virus-receptor inter-

actions of two primate polyoma viruses. J. Biol. Chem. 1995, 270, 1308–1314.

RETRACTED RETRACTED RETRACTED RETRACTED

RET^[R³⁰A^{] K}C^uaTⁿE^{, S}D^.F.;R^ByE^rdT^{, J}R^.C.A^{; B}C^asbT^auE^mD^{, C.}R^{; K}E^imT^{, Y}R^.SA^{. In}C^hiT^bitE^ioD^{n of}R^muE^ciTⁿR^glyA^cosC^ylT^atiE^onD^by

aryl-N-acetyl-a-galactosaminides in human colon cancer cells. J. Biol. Chem. 1989,

264, 19271–19277.

RETRACTED RETRACTED RETRACTED RETRACTED

b-D-ManNAc-(1!4)-D-Glc and b-D-TalNAc-(1!4)-D-Glc Disaccharides

171

RETRACTED RETRACTED RETRACTED RETRACTED

[31] Krist, P.; Kuzma, M.; Pelyvas, I.F.; Simerska, P.; Kren, V. Synthesis of 4-nitrophe-

RETRACTED RETRACTED RETRACTED RETRACTED

nyl 2-acetamido-2-deoxy-b-D-mannopyranoside and 4-nitrophenyl 2-acetamido-2-

deoxy-a-D-mannopyranoside. Coll. Czech. Chem. Commun. 2003, 68, 801–811.

RETRACTED RETRACTED RETRACTED RETRACTED

[32] Pavlıcek, J.; Sopko, B.; Ettrich, R.; Kopecky, V., Jr.; Baumruk, V.; Man, P.;

RETRACTED RETRACTED _ˇRETRACTED R_ˇETRACTED

Havlıcek, V.; Vrbacky, M.; Martinkova, L.; Kren, V.; Pospısil, M.; Bezouska, K. Mol-

ecular characterization of binding of calcium and carbohydrates by an early acti-

RETRACTED RETRACTED RETRACTED RETRACTED

vation antigen of lymphocytes CD69. Biochemistry 2003, 42, 9295–9306.

RETRACTED RETRACTED RETRACTED RETRACTED

[33] Pavlıcek, J.; Kavan, D.; Pompach, P.; Novak, P.; Luksan, O.; Bezouska, K. Lympho-

cyte activation receptors: new structural paradigms in group V of C-type animal

RETRACTED RETRACTED RETRACTED RETRACTED

lectins. Biochem. Soc. Trans. 2004, 32, 1124–1126.

RETRACTED RETRACTED RETRACTED RETRACTED

[34] Corsaro, A.; Pistara, V.; Catelani, G.; D’Andrea, F.; Adamo, R.; Chiacchio, M.A. A

new method for the synthesis of carba-sugar enones (gabosines) using a mercur-

RETRACTED RETRACTED RETRACTED RETRACTED

y(II)-mediated opening of 4,5-cyclopropanated pyranosides as the key-step. Tetra-

hedron Lett. 2006, 47, 6592–6594.

RETRACTED RETRACTED RETRACTED RETRACTED

Products guided by the article

Product name:C₃₂H₅₁NO₁₂

Cas No:1044747-35-4

R&D Labs maybe for 1044747-35-4

Beijing Top Science biological technology co., LTD

Contact:+86-13439059536

Address:15-1705 jre three mile, Beijing 100000,CHINA
Chongqing maohuan Chemicals Co., Ltd

website:http://www.bschem.com

Contact:+86 13996103726

Address:Chongqing Nan'an District Tu Town
Jingzhou TianHe Sci&Tech Chemical Co., Ltd.

Contact:86-716-8331612

Address:Jiangjin Road, #18, High-grade technology industries development district, Jingzhou city, Hubei province
Jining tiansheng chemical co.,ltd.

Contact:+86-537-5158722

Address:ROOM 1011, BLOCK B, CUIDU INTERNATIOAL BUSINESS CENTER, JINING CITY, CHINA
Springchem New Material Technology Co.,Limited

website:http://www.spring-chem.com

Contact:86-21-62885108

Address:602B, Building 1, No. 641, Tianshan Road

Relevant to this article

Enhanced irregular photodimers and switched enantioselectivity by solvent and temperature in the photocyclodimerization of 2-anthracenecarboxylate with modified β-cyclodextrins

Doi:10.1016/j.jphotochem.2018.11.038
(2019)
Highly enantioselective syntheses of chiral β-amino alcohols in the presence of chiral Ti^IV Schiff base complexes as catalysts

Doi:10.1002/ejoc.200800099
(2008)
Stimuli-responsive luminescent liquid crystals: Change of photoluminescent colors triggered by a shear-induced phase transition

Doi:10.1002/anie.200800164
(2008)
Total synthesis of a marine alkaloid from the tunicate Dendrodoa grossularia

Doi:10.1021/ol801375k
(2008)
Methyl Trifluoropyruvate in Cyclocondensation Reactions with N-Substituted Ureas

Doi:10.1134/S1070363219010286
(2019)
Doi:10.1021/jo01052a042
(1962)

Article Doi

Improved preparation of β-D-ManNAc-(1→4)-D-Glc and β-D-TalNAc-(1→4)-D-Glc disaccharides and evaluation of their activating properties on the natural killer cells NKR-P1 and CD69 receptors

DOI: 10.1080/07328300802030845

Source and publish data:

Authors:

Article abstract of DOI:10.1080/07328300802030845

Full text of DOI:10.1080/07328300802030845

Products guided by the article

R&D Labs maybe for 1044747-35-4

Relevant to this article

Hot Product