3-Azido-l,2-diols

Cleavage of 2 -epoxy alcohols.3 The combination of (QHs AlF (1 equiv.) and N3Si(CH3)3 cleaves these epoxides regio- and stereoselectively to provide anti-3-azido-l,2-diols. 

Epoxy alcohols react with Et2AlN3 under mild reaction conditions to afford 3-azido-l,2-diols resulting from the regio- and stereoselective attack of the nucleophile at the C-3 carbon of the epoxides [121]. Here the high regioselectivity observed with both cis- and trans-substituted epoxides is not affected by bulky substituents at C-3 (Sch. 85). 

With added NaNj 3-azido-l,2-diols are obtained. Oxazolines are formed from... 

If , if , 4 )- (lf , 3S, 4 )-4-Acetoxy-3-3-hydroxy-2-oxocyclochexyl acetate (1,2,4)-4-Acetyl-1 -methylcyclohexane-1,2-diol 3-Azido-2-hydroxy-l-phenylpropan-l-one -t3-Azido-2-hydroxy-l-phenylpropan-2-one... 

Ring opening of 3-cyclohexyl-2,3-epoxypropan-l-ol (39) with sodium azide over H-X gave an 85% yield of the isomeric azido diols, 40 and 41, with the vicinol diol, 40, the almost exclusive product. With other zeolites and clays, the yields were lower but the regioselectivity still favored the formation of 40 (Eqn. 22.39). 6... 

Another approach by Naruta and co-workers to the synthesis of 9,9a-dihydro-3H-pyrrolo[l,2-a]indoloquinones was based on photocyclization of a diene and an azidoquinone [23] (Scheme 5). Thus, irradiation of a mixture of two equivalents of 2-azido-5-methoxy-6-methyl-l,4-benzoquinone (40) and one equivalent of doubly protected cis, cfs-2,4-hexadien-l,6-diol (41) gave an in-doloquinone 42 that had the 2,3-trans and 8,9-cis configurations. Selective desilylation followed by mesylation and treatment with DBU at reflux temperature then gave the desired tricyclic compound 43 in 35% overall yield. 

Azido-sugars are frequently prepared by reaction of epoxides with azide ion. 3-Azido-3-deoxy-L-threose 68 was synthesized from cu-but-2-ene-l,4-diol 66 via the Sharpless asymmetic epoxidation product 67, and was converted into 6-azido-6-deoxy-L-galocro-heptulose 69 by an enzyme-catalyzed aldol condensation (Scheme 13). 3-Azido-3-deoxy-L-etythrose, and thence 6-azido-6-deoxy-L-g/uco-heptulose were obtained in a similar way via 4-rerf-butyldiphenylsilyoxy-rraiu-but-2-enal. These and two other azido-heptulose isomers made from the enantiomeric 3-azido-3-deoxy-tetroses, were converted to a- and P-l-homonojirimycin and homomannonojirimycin on hydrogenation. Ethyl 3-azido-2,3-dideoxy-D-eryr/iro-pentopyranoside and its 3-C-methyl analogue 71, R=H or Me, were synthesized from crotonaldehyde or 3-methyl-2-... 

The reduction of 55 gave 56 but mainly (5)-57 showing an e.e. of more than 99%. From the ketoacetate 58 the diol 59 was obtained with high e.e. value [96] high e.e. values were also reported for the reduction of 4-acetylpyridine, 3-(benzyloxy)-l-hydrox-ypropanone, and l-(acyloxy)-3-azido-2-propanols [13]. 

The first total synthesis of siastatin B (1) was achieved from L-ribose by protection of the 2,3-diol, followed by introduction of an azide group on C-5 and oxidation of the anomeric hydroxyl group to give 5-azido-5-deoxy-2,3-0-isopropylidene-L-ribonolactone... 

A l-0-silyl-2,5-cyclohexylidene derivative has been transformed into condur-itol E and 2-deoxy-a//o-inositol in which chirality was introduced using a Sharpless asymmetric epoxidation reaction, and 1,4- and 1,3-cyclohexadienes have been bis-epoxidized and the epoxide rings cleaved with azide to afford di-azido diol compounds which were asymmetrized enzymatically. ... 

The reported synthetic methods for 3 ,4 -dideoxygenation are, however, not compatible with the presence of azido groups. Thus, we have developed a new method for the synthesis of desired 3 ,4 -dideoxy-l,3,2 ,6 -tetraazidoneamine (Scheme 2). (26) The dideoxygenation was carried out at very wild condition via triflation of the 3 , 4 -diol, followed by treatment of Nal and Na2S203,. 

---