Complete Sets of Monosubstituted γ-Cyclodextrins as Precursors for Further Synthesis

Abstract

Regioselective alkylation of γ-cyclodextrin with allyl or propargyl bromide, using optimized reaction conditions, followed by peracetylation of the remaining hydroxyl groups and separation of isomers resulted in the set of peracetylated 2(I)-O-, 3(I)-O- and 6(I)-O-alkylated cyclodextrins in up to 19% yields. Ozonolysis or oxidative cleavage of peracetylated allyl derivatives resulted in a complete set of peracetylated 2(I)-O-, 3(I)-O-, and 6(I)-O-formylmethyl or -carboxymethyl derivatives. All of these derivatives are useful precursors for further preparation of regioselectively monosubstituted derivatives of γ-cyclodextrin.

Monosubstituted Cyclodextrins as Precursors for Further Use

“…-CD α-D-glucopyranosyl 65.9 [86] 14 -CD 5,5,6,6,7,7,7-heptafluorohept-2-en-1-yl 67.77 [55] 15 -CD 4-{8,8′-μ-(sulfido)-[3,3′-commocobalt(III)-bis(1,2-di-68.28 [56] carbaundecaborate)]-8-yl}but-2-en-1-yl 16 -CD 5,6,6,6-tetrafluoro-5-(trifluoromethyl)hex-2-en-1-yl 67.78 [55] 17 -CD 5,5,6,6,7,7,8,8,9,9,10,10,10-tridecafluorodec-2-en-1-yl 67.82 [55] 18 γ-CD allyl 67.58 [55] 19 γ-CD propargyl 67.5 [85] 20 γ-CD formylmethyl 69.7 [85] 21 γ-CD carboxymethyl 70.1 [85] 22 γ-CD 5,5,6,6,7,7,7-heptafluorohept-2-en-1-yl 67.79 [55] 23 γ-CD 5,6,6,6-tetrafluoro-5-(trifluoromethyl)hex-2-en-1-yl 67.81 [55] 24 γ-CD 5,5,6,6,7,7,8,8,9,9,10,10,10-tridecafluorodec-2-en-1-yl 67.81 [55] Eur. …”

“…These derivatives can be used for subsequent alkylation, followed by removal of all remaining benzyl groups. NaOH, H 2 O 9 -- [55] [85] during the deprotection step, usually done by H 2 with Pd catalyst. NaOH, H 2 O 1 0 -- [100] 16 -CD allyl bromide 2 equiv.…”

“…Org. [78,82,83,85,[108][109][110] Per-O-methyl-2 A -O-carboxymethyl--CD was prepared from per-O-methyl-2 A -O-allyl--CD by oxidation with NaIO 4 /RuCl 3 [83] or from per-O-methyl-2 A -O-formylmethyl--CD with NaClO 2 /NaH 2 PO 4 [111] and also by treatment of permethylated 2 A -O-hydroxy--CD with iodoacetate. 2016, 5322-5334 www.eurjoc.org achieved with LiH in DMSO together with a catalytic amount of LiI.…”

“…[96] Per-Omethyl-2 A -O-formylmethyl--CD was prepared from per-Omethyl-2 A -O-allyl--CD by oxidation either with O 3 /PPh 3 [105,113] or with OsO 4 /N-methylmorpholine-N-oxide (NMO) followed by NaIO 4 . [82,85] Scheme 6. [82,85] Scheme 6.…”

Secondary‐Rim γ‐Cyclodextrin Functionalization to Conjugate with C60: Improved Efficacy as a Photosensitizer

“…Among variouss trategies, tosylation and sulfonylation reactions have been probably the most extensively studied in that regard. [25] There is an eed for regioselective ande fficient secondary rim functionalization of g-CD. [15,16] We have delineated ab lueprint strategy consisting of deprotecting per-O-benzylated CDs using diisobutylaluminium hydride (DIBAL-H), which provest ob ev ery efficient because it allows access to CDs with one, two, and up to six different functions on their primary rim.…”