Total Synthesis of the Gastroprotective Substance Ai-77-B and of Analogs
The Diels-Alder adducts 8 of furan to 1-cyanovinyl acetate were converted into (methyl 3-chloro-5-043-chlorobenzoyl)-2,3-dideoxy-alpha-DL-arabino-hexofuranosid )uronic acid ((+/-)-18a) and into (methyl 3-azido-5-0-(3-chlorobenzoyl)-2,3-dideoxy-alpha-DL-ribo-hexofuranosid)ur onic acid ((+/-)-41a). These compounds were condensed to (3S)-3-[(1'S)-1'-amino-3'-methylbutyl]-3,4-dihydro-8-hydroxyisocoumarin hydrochloride ((-)-2); the resulting mixtures of diastereoisomeric amides were transformed and separated to give the gastroprotective substance AI-77-B ((-)-1) and analogues.
Keywords: Bacillus-pumilus ai-77 ; silyl enol ethers ; pure ; 7-oxabicyclo<2.2.1>hept-5-en-2-yl derivatives ; amino-acid moiety ; microbial products ; naked sugars ; pharmacological activity ; carbonyl-compounds ; chemical nature ; oxidation
Univ lausanne,chim sect,rue barre 2,ch-1005 lausanne,switzerland.
Record created on 2005-11-09, modified on 2016-08-08