Total syntheses of (+)- and (−)-1-deoxynojirimycin (1,5-dideoxy-1,5-imino-d- and l-glucitol) and of (+)- and (−)-1-deoxyidonojirimycin (1,5-dideoxy-1,5-imino-d- and l-iditol) via furoisoxazoline-3-aldehydes

Synthesis of L‐Furanomycin and Its Analogues via Furoisoxazolines

“…Next, the amino group in the side-chain and the C=C bond of the dihydrofuran ring had to be elaborated in order to obtain structures 22-24. As expected from earlier work, [17][18][19][20] reduction of the isoxazolines 12, 14, and 15 with lithium aluminium hydride in THF/diethyl ether led to the corresponding 1,3-amino alcohols with high exo selectivity (Ͼ95:5 from NMR analyses). Hydride attack from the sterically less hindered exo side of the furoisoxazolines gave the erythro-1,3-amino alcohols.…”

“…The relative configuration at C2/C2Ј (threo) would result from furoisoxazoline reduction, as experienced earlier. [17][18][19][20] The 2,5-trans-disubstituted dihydrofuryl part in A might be formed from B by S N 2Ј hydride addition which would necessitate attack from the most hindered endo face of the bicycle. All attempts to achieve this failed, however, so the hydration of B by anti addition of OH/H was considered next in order to set up the 4,5-cis/ 3,4-trans methyl/diol part (see D).…”

Recent advances in the chemistry of azapyranose sugars

“…An asymmetric synthesis using a chiral resolution was reported by Vogel et al (Scheme 2). 71 Isoxazoline (±)-55 was derived from 2-nitroethanal diethyl acetal and furan via a [2+3] di-polar cycloaddition (75%). 72 Using osmium tetraoxide and N-methylmorpholine N-oxide, bis-hydroxylation was achieved to give the 6-exo isomers (±)-56 (88%) as a 3:1 mixture of anomers.…”

“…treatment with an ion-exchange resin furnished azasugar 220.Vogel et al have adapted their DNJ synthesis towards the synthesis of 1-deoxyidonojirimycin 219, and its enantiomer 1-deoxy-L L-idonojirimycin 260, utilising their enantiomerically pure aldehydes (À)-57 and (+)-57 (seeScheme 2) 71. From (+)-57, a hydride reduction led to the aminodiol (À)-261 (Scheme 33).…”

Asymmetric Syntheses of New Polyhydroxylated Quinolizidines: Cross-Aldol Reactions of 7-Oxabicyclo[2.2.1]heptan-2-one and 3a,4a,7a,7b-Tetrahydro[1,3]dioxolo[4,5]furo[2,3-d]isoxazole-3-carbaldehyde Derivatives

“…The latter could be generated by reduction of the furoisoxazoline derivatives of type B and acetal hydrolysis. Cross-aldolization of enantiomerically pure 7-oxabicyclo[2.2.1]heptan-2-one (À)-25 with aldehydes ()-26 and (À)-26 that have been obtained enantiomerically pure [24] should enable us to generate a number of required aldols of type D. Analogous 7-oxabicyclo[2.2.1]heptanone derivatives have been converted to anhydrogalacturonic esters of type C that can be reduced to the corresponding 1,4-anhydro-galactopyranose derivatives B [23] [25] [26]. Both types of starting materials, (À)-25 (PhSeCl adduct [27] to a naked sugar of the first generation [28]) and ()-26 or (À)-26, are derived from inexpensive furan [24] [29].…”