Higher Sucrose Analogs: Homologation of a Glucose Unit of Sucrose by Two Carbon Atoms |
| |
Authors: | Sławomir Jarosz Mateusz Mach |
| |
Institution: | Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka, 44, 01-224, Warszawa E-mail: SLJAR@ICHF.EDU.PL |
| |
Abstract: | Abstract The primary hydroxyl groups (at C-6 and C-6′) in 2,3,4,3′4′-penta-O-benzyl-l′-O-methoxymethyl sucrose (2) can be reactively differentiated with tert-butyldiphenylsilyl chloride. Reaction of 2 with TBDPSCl afforded only one monosilylated product protected at C-6′ (6). The regioisomeric monoprotected sucrose 8 was prepared by selective deprotection of the double silylated derivative 7. Compound 6 was converted into 2,3,4,3′,4′-penta-O-benzyl-6-carbomethoxymethylidene-1′-O-methoxymethylsucrose 10 in three steps. Osmylation of the double bond in 10 afforded stereoisomeric homologated sucroses: 11a 6(S),7(R)] and 11b 6(R),7(S)] in the ratio 3:2. A large downfield shift of the H-1 (up to 0.5 ppm) was observed for 6′-silylated derivatives. |
| |
Keywords: | |
|
|