Synthesis Of Natural Alpha-6-Dehydroxy-6-Aminoglucoglycerolipids

Two natural 6-dehydroxy-6-aminoglucoglycerolipids were first synthesized in a convenient approach. The key step was the selective alpha-glycosylation of 6-dehydroxy-2,3,4-tri-O-benzyl-6-amino-D-glucopyranosyl trichloroacetimidate donor 10 with (S)-isopropyleneglycerol using diethyl ether as glycosylation solvent to give 3-O-(2,3,4-tri-O-benzyl-6-dehydroxy-6-benzyloxycarbonylamino-alpha-D-glucopyranoyl)-1,2-O-isopropylene-sn-glycerol 7. Removal of acetonide group of 7 and acylation with various fatty acids, then deprotection of benzyl and Cbz groups and selective acylation of the amino group afforded the marine natural glycoglycerolopids of sn-1,2-dipalmitoyl3-(N-palmitoyl-6-dehydroxy-6-amino-alpha-glucosyl)glycerol 3 and sn-1-palmitoyl-2-myristoyl-3-(N-stearoyl-6-dehydroxy-6-amino-alpha-glucosyl)glycerol 4. The structures of the synthetic samples were identified by H-1, C-13 NMR, and HRESIMS.