Showing papers on "Ferrier rearrangement published in 2006"
TL;DR: A convergent stereocontrolled total synthesis of (-)-kendomycin has been achieved with an effective Petasis-Ferrier union/rearrangement tactic to construct the sterically encumbered tetrahydropyran ring.
Abstract: A convergent stereocontrolled total synthesis of (−)-kendomycin (1) has been achieved The synthesis proceeds with a longest linear sequence of 21 steps, beginning with commercially available 2,4-dimethoxy-3-methylbenzaldehyde (12) Highlights of the synthesis include an effective Petasis−Ferrier union/rearrangement tactic to construct the sterically encumbered tetrahydropyran ring, a ring-closing metathesis to generate the C(4a−13−20a) macrocycle, an effective epoxidation/deoxygenation sequence to isomerize the C(13,14) olefin, and a biomimetic quinone−methide−lactol assembly to complete the synthesis
78 citations
TL;DR: In this article, a simple, mild, efficient and environmentally benign method for the synthesis of 2,3-unsaturated allyl C-glycosides and O- and S-Glycosides is described using phosphomolybdic acid supported on silica gel as a reusable catalyst with high α-selectivity.
43 citations
TL;DR: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing 2',3'-dideoxy pyranosyl nucleosides easily by means of cleaner reaction profiles, short reaction times, mild reaction conditions, good stereoselectivity, and good recoverability of the commercially available catalyst.
Abstract: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing 2',3'-dideoxy pyranosyl nucleosides easily by means of cleaner reaction profiles, short reaction times, mild reaction conditions, good stereoselectivity, and good recoverability of the commercially available catalyst.
24 citations
TL;DR: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing high yields of products, cleaner reaction profiles, short reaction times, mild reaction conditions, high stereoselectivity and recoverability of the catalyst which is also commercially available as mentioned in this paper.
Abstract: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing high yields of products, cleaner reaction profiles, short reaction times, mild reaction conditions, high stereoselectivity and recoverability of the catalyst which is also commercially available.
18 citations
TL;DR: A variety of 2,3-unsaturated O-glycosides have been prepared by the Ferrier rearrangement of acetyl protected glycals under microwave irradiation using silica gel as an acid catalyst as discussed by the authors.
12 citations
TL;DR: In this paper, the NbCl 5 -catalyzed reaction of primary and secondary alcohols with tri-Oacetyl-D-glucal is described, and exclusive formation of α-anomers of eight 2,3-unsaturated glycosides (3a-h) in high yields has been observed.
Abstract: NbCl 5 -catalyzed reaction of primary and secondary alcohols with tri-Oacetyl-D-glucal is described. Exclusive formation of α-anomers of eight 2,3-unsaturated glycosides (3a-h) in high yields has been observed. Among eight unsaturated glycosides (3a-h) prepared, two of them (3d,e) are new. A new mechanism of the formation of (3a-h) from tri- O-acetyl-D-glucal and an alcohol assisted by NbCl 5 as a catalyst has been suggested.
9 citations
TL;DR: In this paper, the synthesis of the δ-lactonic fragment of pironetin (1), a natural product with outstanding antimitotic properties, was reported, achieved from commercially available tri-O-acetyl-D-glucal (6) that was employed as starting material for the preparation of ethyl ketone 4, through a synthetic sequence that included a Ferrier rearrangement of 6 and suitable functional group manipulations of the resulting O−glycoside 7 to obtain the 4−ethyl glycoside 11, together with a series
4 citations
TL;DR: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing high yields of products, cleaner reaction profiles, short reaction times, mild reaction conditions, high stereoselectivity and recoverability of the catalyst which is also commercially available as mentioned in this paper.
Abstract: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing high yields of products, cleaner reaction profiles, short reaction times, mild reaction conditions, high stereoselectivity and recoverability of the catalyst which is also commercially available.
3 citations
TL;DR: In this paper, a simple, mild, efficient and environmentally benign method for the synthesis of 2,3-unsaturated allyl C-glycosides and O- and S-Glycosides is described using phosphomolybdic acid supported on silica gel as a reusable catalyst with high α-selectivity.
Abstract: A simple, mild, efficient and environmentally benign method for the synthesis of 2,3-unsaturated allyl C-glycosides and O- and S-glycosides is described using phosphomolybdic acid supported on silica gel as a reusable catalyst with high α-selectivity.
1 citations
TL;DR: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing 2',3'-dideoxy pyranosyl nucleosides easily by means of cleaner reaction profiles, short reaction times, mild reaction conditions, good stereoselectivity, and good recoverability of the commercially available catalyst as mentioned in this paper.
Abstract: Er(OTf) 3 is a useful catalyst for the Ferrier rearrangement furnishing 2',3'-dideoxy pyranosyl nucleosides easily by means of cleaner reaction profiles, short reaction times, mild reaction conditions, good stereoselectivity, and good recoverability of the commercially available catalyst.
1 citations
TL;DR: In this article, a palladium mediated modified protocol has been developed for the glycosidation of an aromatization prone xylo-furanoid glycal for the synthesis of D-D4FC.
Abstract: D-D4FC ( 1 ) is an anti-HIV agent currently under phase II clinical trial (Pharmaset Inc) Its molecular architecture is suitable for a Ferrier rearrangement kind of operation on a furanoid glycal to fix the position of the double bond and the relative stereochemistry Despite the fact that classical Ferrier rearrangement does not work on furanoid glycals, a palladium mediated modified protocol has been developed for the glycosidation of an aromatization prone xylo-furanoid glycal ( 5 ) for the synthesis of D-D4FC
TL;DR: In this article, 2-C -acetoxymethyl glycal derivatives react with aliphatic alcohols in the presence of InCl 3 to furnish the corresponding 2-c -methylene glycosides in excellent yields and with exclusive α-selectivity.
Abstract: 2- C -Acetoxymethyl glycal derivatives react with aliphatic alcohols in the presence of InCl 3 (30 mol %) to furnish the corresponding 2- C -methylene glycosides in excellent yields and with exclusive α-selectivity except for the methyl 2- C -methylene glycosides, which are formed in ∼2:1 anomeric ratio in favour of the α-anomer. The reaction of 2- C -acetoxyglycals with phenols, however, produces the corresponding chiral carbohydrate-derived pyranobenzopyran derivatives via initial Ferrier rearrangement followed by tandem cyclization in excellent yields and moderate to high stereoselectivities in favour of the corresponding 10a- R -pyrano[2,3- b ][1]benzopyran derivatives.
TL;DR: In this paper, the synthesis of the δ-lactonic fragment of pironetin (1), a natural product with outstanding antimitotic properties, was reported, achieved from commercially available tri-O-acetyl-D-glucal (6) that was employed as starting material for the preparation of ethyl ketone 4, through a synthetic sequence that included a Ferrier rearrangement of 6 and suitable functional group manipulations of the resulting O−glycoside 7 to obtain the 4−ethyl glycoside 11, together with a series
Abstract: The synthesis of the δ‐lactonic fragment of pironetin (1), a natural product with outstanding antimitotic properties, is reported. The synthesis was achieved from commercially available tri‐O‐acetyl‐D‐glucal (6) that was employed as starting material for the preparation of ethyl ketone 4, through a synthetic sequence that included a Ferrier rearrangement of 6 and suitable functional group manipulations of the resulting O‐glycoside 7 to obtain the 4‐ethyl glycoside 11, together with a series of 4‐C‐alkyl modified derivatives. The completion of the synthesis of 4 was performed via chain elongation at C‐6 by the introduction of a nitrile group and subsequent reduction, nucleophilic attack with ethyl magnesium bromide, and, finally, oxidation of the resulting alcohol 20.
TL;DR: A variety of 2,3-unsaturated O-glycosides have been prepared by the Ferrier rearrangement of acetyl protected glycals under microwave irradiation using silica gel as an acid catalyst.
Abstract: A variety of 2,3‐unsaturated‐O‐glycosides have been prepared by the Ferrier rearrangement of acetyl protected glycals under microwave irradiation using silica gel as an acid catalyst. Environmental friendliness, high yields, and short reaction times are the key features of this method. Furthermore, the method was applicable not only to the Ferrier reaction of 3,4,6‐tri‐O‐acetyl glucal and 3,4,6‐tri‐O‐acetyl galactal but also to the Ferrier reaction of 3,4‐di‐O‐acetyl arabinal.