L-Tagatose

Not able to reproduce a previously reported approach [30] to (5) from D-galactose, Tyler and co-workers designed an efficient sequence starting from L-sorbose [46], via a partially protected 6-azido-6-deoxy-L-tagatose derivative, and obtained an overall yield of 20%. Ogawa and co-workers [47] prepared D-galactonojirimycin as well as 1-deoxygalactonojirimycin from L-quebrachitol (11), a natural product found in the serum of the rubber tree. 

Finally, L-sorbose (25) and L-tagatose (L-iyxo-2-hexulose) (40) have... 

A D,L-tagatose preparation (m. p. 119-121°) has been obtained83 by recrystallizing together equal quantities of d- and L-tagatose. 

From 3,6-Anhydromonosaccharide OsotriazdlesA —The osotriazoles of the 3,6-anhydro derivatives of D-psicose and L-tagatose gave the same dialdehyde monohydrate, to which the hemialdal structure (33) was assigned. The mirror-image product (34) was obtained from oxidation of the HC=N... 

The aldol reactions of 25 with appropriate aldehydes in the presence of L-proline have been also used by Enders and co-workers [141,142,143] for the preparation of aminosugars D-ery-f/tro-pentos-4-ulose, 5-amino-5-deoxy-L-psicose (37a), and 5-amino-5-deoxy-L-tagatose (37b) derivatives. 

L-Fucose 6-deoxy-L-tagatose arabinoisomer- Escherichia coli 46, 47... 

T. Mukaiyama, Y. Yuki, and K. Suzuki, The stereoselective synthesis of L-tagatose An application of Zn (II) mediated highly stereoselective addition of 2-furyllithium to polyoxygenated aldehyde, Chem. Lett., 1169 (1982). 

On treatment with 5% sodium hydrogen carbonate for 1.5 h, ascorbigen (18) formed the unstable product 19 and, after longer exposure times, the 6-deoxy-L-tagatose derivative... 

The key-step in the synthesis of 5-(7-methyl-D-mannose from L-quebrachitol was the glycol cleavage of the isopropyUdene derivative 15 (Scheme 6). L-Tagatose was prepared by a similar, but extended reaction sequence incorporating a Mitsunobu inversion at the future C-4. L-Olucose has been synthesized in many steps from cycloheptatriene (Scheme 7) via the meso-intermediate 16 which was desymmetrizized by enzymic monoacetylation. Transformation to the allylic alcohol 17 involved inter alia stereoselective oxygenation and cis-hydroxylation. Ozonolysis, followed by... 

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