Asymmetric total syntheses of (+)-2,5-dideoxy-2,5-imino-d-glucitol [(+)-DGDP] and (−)-1-deoxymannojirimycin [(−)-DMJ] via an extended chiral 1,3-oxazine

Recent advances in the total synthesis of polyhydroxylated alkaloids via chiral oxazines

“…To introduce a new stereogenic center and produce anti , syn , anti -oxazine, we conducted OsO 4 (osmium tetroxide)-catalyzed dihydroxylation (Table 8). 11 We explored various conditions to optimize the reaction and achieved highly anti -selective reactions with good yields (entries 1–3).…”

“…(+)-1-Deoxynojirimycin (2), 7 (+)-1-deoxygalactonojirimycin (3), 9 (−)-1-deoxygulonojirimycin (4), 9 and (−)-1-deoxymannojirimycin (5). 11 (+)-1-Deoxynojirimycin ((+)-DNJ, 2), 65,84,102,103 (+)-1-deoxygalactonojirimycin ((+)-galacto-DNJ,…”

“…This group includes relatively simple molecules like (−)-cassine ( C1 ), (+)-spectaline ( S 3 ), 3 (+)- l -733 060 ( L1 ), 4 (2 S ,3 R )-3-hydroxypipecolic acid ( P3 ), 5 and d -fagomine ( 1 ), 6 featuring three contiguous stereogenic centers. In contrast, more intricate compounds boasting four or more contiguous chiral carbons comprise (+)-1-deoxynojirimycin ( 2 ), 7 (+)-1-deoxygalactonojirimycin ( 3 ), 8,9 (−)-1-deoxygulonojirimycin ( 4 ), 9,10 (−)-1-deoxymannojirimycin ( 5 ), 11 pancratistatin ( P 5 ), and 7-deoxypancratistatin ( D5 ). Notably, derivatives of 2 , such as miglitol ( M2 , Glyset®) and miglustat ( M3 , Zavesca®), containing N -alkyl substitutions, are particularly selected for the treatment of diabetes mellitus or type 1 Gaucher disease due to their inhibitory effects on glucosidases.…”

“…Pyrrolidine alkaloids (Fig. 1 and 2b) such as (+)-preussin ( P4 ), 12 (+)-detoxinine ( D1 ), 13 (−)-anisomycin ( 6 ), 14 DAB-1 ( 7 ), 6 (+)-DMDP ( 8 ), 7 (+)-DGDP ( 9 ), 11 (+)-radicamine B ( 10 ), 15 and (+)-broussonetine D ( 11 ) 16 have been extracted from plant sources.…”

Recent advances on the synthesis of natural pyrrolizidine alkaloids: alexine, and its stereoisomers

“…In another study, Myeong and Ham achieved the total synthesis of alexine 1 and (−)-7-epi-alexine 13 from anti,syn,anti-oxazine 153 [53]. Treatment of diol 153 (obtained from 152) [54] with 2,2-dimethylpropanoyl chloride (PivCl) gave compound 154, which was mesylated, followed by oxazine ring cleavage, and simultaneously induced cyclization to afford functionalized pyrrolidine 155. Protection of secondary alcohol 155 by a methoxymethyl (MOM) group gave the compound 156, which was deprotected to give primary alcohol 157.…”