Chatterjea, J. N.; Singh, K. R. R. P.; Jha, I. S., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1986, vol. 25, p. 796 - 798
First totalsynthesis of AI-77-B (1), a gastroprotectivesubstance from Bacillus pumilus AI-77, was achieved in a stereoselective and convergent manner. In this synthesis, the dihydroisocoumarin part 2 was constructed in one step through 1,2-addition of the benzylic anion 17b to Boc-L-leucinal 7b. The hydroxy amino acid 4 was elaborated from (R)-glutamic acid in a highly stereoselective manner. Condensation
New Syntheses of Lunularic Acid and Some of Its Derivatives Efficient and convenient procedures are reported for the synthesis of lunularic acid (2) and for some of its derivatives on a preparative scale starting from the methyl ether 5 or the acetate 12 of ethyl 6-methylsalicylate (4) and introducing the bibenzyl moiety by metalation/ alkylation or by bromination / Wittig reaction/ hydrogenation sequences.