References and Notes
- 1
Kartha KPR.
Jennings HJ.
J.
Carbohydr. Chem.
1990,
9:
777
- 2
Kumar R.
Tiwari P.
Maulik PR.
Misra AK.
Eur. J. Org. Chem.
2006,
74
- 3
Mukhopadhyay B.
Kartha KPR.
Russell DA.
Field RA.
J.
Org. Chem.
2004,
69:
7758
-
4a
Tai A.-A.
Kulkarni SS.
Hung S.-C.
J. Org. Chem.
2003,
68:
8719
-
4b
Tiwari P.
Kumar R.
Maulik R.
Misra AK.
J. Carbohydr. Chem.
2005,
24:
723
-
4c
Lin C.-C.
Huang L.-C.
Liang P.-H.
J.
Carbohydr. Chem.
2006,
25:
303
-
4d
Dasgupta S.
Rajput VK.
Roy B.
Mukhopadhyay B.
J. Carbohydr. Chem.
2007,
26:
91
-
4e
Valerio S.
Iadonisi A.
Adinolfi M.
Ravidà A.
J. Org. Chem.
2007,
72:
6097
-
5a
Wang C.-C.
Lee J.-C.
Luo S.-Y.
Kulkarni SS.
Huang Y.-W.
Lee C.-C.
Chang K.-L.
Hung S.-C.
Nature
(London)
2007,
896
-
5b
Français A.
Urban D.
Beau J.-M.
Angew.
Chem. Int. Ed.
2007,
46:
8662
-
6a
De Belder AN.
Adv. Carbohydr.
Chem. Biochem.
1965,
20:
219
-
6b
De Belder AN.
Adv. Carbohydr. Chem. Biochem.
1977,
34:
179
- 7
Kihlberg J.
Frejd T.
Jansson K.
Magnusson G.
Carbohydr. Res.
1986,
152:
113
-
8a
Barili PL.
Berti G.
Catelani G.
Colonna F.
Marra A.
Tetrahedron Lett.
1986,
27:
2307
-
8b
Foster AB.
Overend WG.
Stacey M.
Wiggins LF.
J.
Chem. Soc.
1949,
2542
- 9
Hung S.-C.
Chen C.-S.
J. Chin. Chem. Soc.
2000,
47:
1257
- 10
Mukherjee D.
Ali Shah B.
Gupta P.
Taneja SC.
J. Org. Chem.
2007,
72:
8965
- 11
Freudenberg K.
Hixon RM.
Ber. Dtsch. Chem. Ges.
1923,
56:
2119
- 12
Winnik FM.
Carver JP.
Krepinsky JJ.
J. Org. Chem.
1982,
47:
2701
- 13
Wood HB.
Diehl HW.
Fletcher HG.
J. Am. Chem. Soc.
1957,
79:
1986
- 14
Lipták A.
Imre J.
Nanási P.
Carbohydr.
Res.
1981,
92:
154
- 15
Boulineau FP.
Wei A.
Carbohydr. Res.
2001,
334:
271
- 16
Kartha KPR.
Tetrahedron Lett.
1986,
27:
3415
-
17a
Chen C.-T.
Weng S.-S.
Kao J.-Q.
Lin C.-C.
Jan
M.-D.
Org. Lett.
2005,
7:
3343
-
17b
Tsunoda T.
Suzuki M.
Noyori R.
Tetrahedron
Lett.
1980,
21:
1357
-
18a
Chen C.-T.
Weng S.-S.
Kao J.-Q.
Lin C.-C.
Jan
M.-D.
Org. Lett.
2005,
7:
3343
-
18b
Tsunoda T.
Suzuki M.
Noyori R.
Tetrahedron
Lett.
1980,
21:
1357
-
Bizier NP.
Atkins SR.
Helland LC.
Colvin SF.
Twitchell JT.
Cloninger MJ.
Carbohydr.
Res.
2008,
343:
1814 ;
and references therein
- 20
Chao C.-S.
Chen M.-C.
Lin S.-C.
Mong K.-KT.
Carbohydr. Res.
2008,
343:
957 ; and references therein
-
21a
Qiu D.
Koganty RR.
Tetrahedron
Lett.
1997,
38:
45
-
21b
Mong TK.-K.
Wong C.-H.
Angew.
Chem. Int. Ed.
2002,
41:
4087
-
21c
Fan R.-H.
Achkar J.
Hernández-Torres JM.
Wei A.
Org.
Lett.
2005,
7:
5095
-
21d
Lopin C.
Jacquinet J.-C.
Angew. Chem. Int. Ed.
2006,
45:
2547
-
21e
Manabe S.
Ishii K.
Ito Y.
J.
Org. Chem.
2007,
72:
6107
- 22
Mukhopadhyay B.
Russell DA.
Field RA.
Carbohydr. Res.
2005,
340:
1075
- 23
Mukhopadhyay B.
Tetrahedron
Lett.
2006,
47:
4337
- 24 Compound 4 was
obtained by literature procedure reported in: Ahn YM.
Gray GR.
Carbohydr.
Res.
1997,
298:
279
- 26 Compound 12 was
obtained by literature procedure reported in: Kondo H.
Ichikawa Y.
Wong C.-H.
J.
Am. Chem. Soc.
1992,
114:
8148
- 28
Larsen K.
Olsen CE.
Motawia MS.
Carbohydr. Res.
2003,
338:
199
- 29
Mong TK.-K.
Huang C.-Y.
Wong C.-H.
J.
Org. Chem.
2003,
68:
2135
- 32
Ziegler T.
Herold G.
Liebigs Ann. Chem.
1994,
859
- 33
Nishida Y.
Dohi H.
Uzawa H.
Kobayashi K.
Tetrahedron Lett.
1998,
39:
8681
- 34 In
Monosaccharides:
Their Chemistry and their Roles in Natural Products
Collins PM.
Ferrier RJ.
John Wiley and Sons;
New
York:
1996.
p.389-405
- 35
Lu K.-C.
Hseih S.-Y.
Patkar LN.
Chen C.-T.
Lin
C.-C.
Tetrahedron
2004,
60:
8967
25 Unprotected thioglycosides 5-10 were
derived from the corresponding peracetyl thioglycosides by Zemplèn deacetylation.
Peracetyl thioglycosides were prepared by literature procedure reported
in ref. 20.
27 Preparatory procedures of compounds 3 and 11 were described
in supporting information.
30
General One-Pot
Benzylidenation-Acetylation Procedure
for the Preparation of 2 and 13-20
TsOH
(10-32 mol%, Table
[¹]
)
was added into a stirring mixture of carbohydrate substrate (1.0
equiv of methyl α-d-glucopyranoside, 3-8, 10, or 11) and
PhCH(OMe)2 (1.5 equiv) in MeCN under N2. Upon
complete conversion into benzylidene acetal intermediate as assessed
by TLC, Ac2O (1.5 equiv per OH, total OH equals to the
sum of OH of acetal intermediate plus MeOH released from acetalating reagent)
was added, and the reaction temperature was brought up to 40 or
50 ˚C (Table
[¹]
).
Specific reaction conditions are detailed in the supporting information.
Upon complete acetylation as assessed by TLC, excess EtOAc
(4 × volume
of MeCN used) was added to the mixture, which was then washed with
sat. NaHCO3, brine, dried over MgSO4, and
concentrated for purification by flash column chromatography over
SiO2. Elution with EtOAc-hexane mixture afforded
the compounds 2 and 13-20.
31
General One-Pot
Isopropylidenation-Αcetylation Procedure
for Preparation of 21-24
TsOH
(5-10 mol%, Table
[¹]
)
was added into a stirring mixture of unprotected thioglycoside (1.0
equiv of 5, 6, 9, or NANA ester 12),
and Me2CH(OMe)2 (1.5 equiv) in acetone. The
mixture was stirred at r.t. or 40 ˚C under N2.
Upon complete conversion into glycosyl ketal intermediate as assessed
by TLC, Ac2O (1.5 equiv per OH, total OH equals to OH
from glycosyl acetal intermediate plus MeOH released from acetalating
reagent) was added, and the reaction temperature was brought up
to 35 or 40 ˚C (Table
[¹]
).
Specific reaction conditions for preparation of compounds 21-24 were
detailed in the supporting information. Upon complete acetylation
as assessed by TLC, excess EtOAc (4 × volume of MeCN used)
was added to the mixture, which was then washed with sat. NaHCO3,
brine, dried over MgSO4, and concentrated for purification
by flash column chromatography over SiO2. Elution with
EtOAc-hexane mixture afforded compounds 21-24.
36 For acid-catalyzed one-pot acetalation-acetylation, unnecessary
prolonged reaction time would compromise the yield of reaction due
to the cleavage of the acetal function.
