Total synthesis of optically active N-benzoyldaunosamine from an azetidinone

Hauser, Frank M.; Rhee, Richard P.; Ellenberger, Suzanne R.

doi:10.1021/jo00186a031

Cited by 35 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cooled reaction mixture was neutralized with saturated aqueous sodium hydrogen carbonate, the methanol was evaporated off, and the residue was extracted with ethyl acetate (3 x 100 ml). The organic layer was washed with brine, dried, and evaporated to afford the crude P-amido ester (15) which was further purified by passage through a silica gel column (50 g) and eluted with 1 : 9 ethyl acetate-hexane mixture to yield (73%) pure ester ( 15 (18) and (19).-To a solution of the ester (15) (2.8 g, 10 mmol) in aqueous acetone (30 ml) (acetone-water 2: 1) was added osmium tetraoxide (ca. 25 mg) and N-methylmorpholine N-oxide (1.2 g, 10 mmol).…”

Section: Cis-3-azido-l-(4-methoxyphenyl)-4-styrylazetidin-2-one (8b)mentioning

confidence: 99%

“…The solution was stirred for 24 h. Then another batch (1.2 g, 10 mmol) of N-methylmorpholine N-oxide was added and the mixture was stirred for an additional 24 h. The reaction mixture was filtered and the filtrate was evaporated to dryness. The residue was chromatographed over a silica gel column which was eluted with hexane-ethyl acetate (1 : 1) to obtain the two isomeric lactones (18)…”

Section: Cis-3-azido-l-(4-methoxyphenyl)-4-styrylazetidin-2-one (8b)mentioning

confidence: 99%

“…The next step in the synthesis was stereocontrolled glycol formation from the double bond in compound (15); to this end compound (15) was subjected to reaction with osmium tetraoxide in the presence of N-methylmorpholine N-oxide. However, the expected diols (16) and (17) were not obtained; instead, the incipient glycol from the alkene (15) underwent rearrangement to form, in 67% yield, two lactones (18) and (19) in the ratio 1 :2. These lactones could be separated by column chromatography.…”

mentioning

confidence: 99%

“…The smaller coupling indicates a dihedral angle close to 90", and the larger coupling, a dihedral angle near 0". From a model of the lactones it can be seen that compound (18) must have a trans relationship between 4-H and 3-H while in compound (19) this relationship must be cis. The reduction of y-lactones to pyranosides with diisobutylaluminium hydride is well known.'…”

mentioning

confidence: 99%

See 3 more Smart Citations

Studies on lactams. Part 74. An approach to the total synthesis of amino sugars viaβ-lactams

Manhas¹,

Hegde²,

Wagle³

et al. 1985

J. Chem. Soc., Perkin Trans. 1

View full text Add to dashboard Cite

Convenient intermediates for mono-and di-amino sugars related to antibiotics can be prepared in a stereocontrolled fashion by the rearrangement of 3,4-disubstituted azetidin-2-ones which in turn can be synthesized by stereoselective annelation of certain imino compounds by substituted acetic acid derivatives.In the course of our studies on p-lactams we have conducted stereocontrolled syntheses of various disubstituted azetidin-2ones (1). We have noted previously the potential usefulness of plactams as synthons for diverse types of heterocycles.2 We describe here the use of suitably substituted p-lactams as intermediates for various members of a large and valuable family of compounds: the amino sugars. These are important ingredients of three broad classes of biologically active antibiotics, namely, amino glycosides, macrolides, and anthracyclins, besides some miscellaneous antibiotics.Many amino glycosides, such as streptomycin, gentamycin, kanamycin, neomycin, sisomycin, etc., are in use as antibacterial drugs. Macrolides constitute a large class of active antibiotics; e.g., erythromycin, oleandomycin, spiramycin, etc., are in clinical use. Anthracyclins, e.g. daunomycin, adriamycin, and carminomycin, are highly effective against a wide variety of tumours.Structural modification of these antibiotics has often involved the synthesis of various amino sugars. Several review^^-^ deal with naturally occurring amino sugars and their parent antibiotics. Our goal is to devise stereocontrolled and, preferably, enantioselective synthesis of naturally occurring amino sugars as well as their unusual analogues.General Strategy.-3,4-Disubstituted azetidin-Zones (1) can be cleaved to provide j3-amino acid derivatives (2) which can in turn be modified to correspond to the structural features of various amino sugars (Scheme 1). Conversion of the carboxy group into an aldehyde would produce aldoses (3) while ketoses (5) would be derived from a ketone prepared from the carboxy group. The relative configuration of sugar carbons carrying the Z and NH, groups would depend on the cis or trans configuration of the starting p-lactam. Useful Z groups would be OMe, N3, and SR; the last two would lead to a diamino sugar and a deoxy sugar (after desulphurization), respectively. The size of the Y group would determine the number of carbons in the sugar backbone.Reduction of the carboxy group in (2) to a primary alcohol and modification of Y would provide a sugar of type ( 4 ) -a monoamino or diamino aldose. Yet other structural variations could be realized by starting with appropriate 3,3-disubstituted and/or 4,4-disubstituted azetidin-2-ones. The use of optically active p-lactams as starting material would, of course, lead to optically active amino sugars.Starting Materials.-Previous work in our laboratory and elsewhere has shown that Schiffs bases (6) are easily obtained in good yield from %gunsaturated aldehydes and arylamines and that annelation of such imino compounds provides stereospecific access to racemic P-lactams (7a) (see Scheme ...

show abstract

Section: Cis-3-azido-l-(4-methoxyphenyl)-4-styrylazetidin-2-one (8b)mentioning

confidence: 99%

Section: Cis-3-azido-l-(4-methoxyphenyl)-4-styrylazetidin-2-one (8b)mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Studies on lactams. Part 74. An approach to the total synthesis of amino sugars viaβ-lactams

Manhas¹,

Hegde²,

Wagle³

et al. 1985

J. Chem. Soc., Perkin Trans. 1

View full text Add to dashboard Cite

show abstract

“…It is not surprising that the Diels-Alder reaction has often been employed in this field of natural product synthesis because it combines C-C bond formation with regio-and diastereoselectivity at several centers 93 and importantly because commonly all six atoms become part of the target pyranose ring. Nevertheless, in selected examples it was demonstrated that [2+2] 94,95 and [2+3] cycloadditions can equally well be utilized to target deoxy sugars as it is exemplified in the following.…”

Section: Cycloaddition Strategiesmentioning

confidence: 99%