Friedlander reaction between methyl acetoacetate and 2,4-diaminobenzaldehyde provided quinoline 11. Subsequent tosylation, reduction, silylation, and then oxidation led to aldehyde 15. The latter was subjected to a Pictet-Spengler reaction with tryptophan methyl ester that yielded product 16, and then desilylation gave the lavendamycin analogue 17. This compound was oxidized by Dess-Martin periodinane, and the cyclized derivative 18 was obtained via a hemiaminal intermediate. The same sequence from 2,4-diamino-5-methoxybenzaldehyde or from (2,4-diaminophenyl)propan-3-one led to compounds 30 and 31, or 40 and 41, respectively. (C) 2008 Elsevier Ltd. All rights reserved.
Friedlander reaction between methyl acetoacetate and 2,4-diaminobenzaldehyde provided quinoline 11. Subsequent tosylation, reduction, silylation, and then oxidation led to aldehyde 15. The latter was subjected to a Pictet-Spengler reaction with tryptophan methyl ester that yielded product 16, and then desilylation gave the lavendamycin analogue 17. This compound was oxidized by Dess-Martin periodinane, and the cyclized derivative 18 was obtained via a hemiaminal intermediate. The same sequence from 2,4-diamino-5-methoxybenzaldehyde or from (2,4-diaminophenyl)propan-3-one led to compounds 30 and 31, or 40 and 41, respectively. (C) 2008 Elsevier Ltd. All rights reserved.
Friedlander reaction between methyl acetoacetate and 2,4-diaminobenzaldehyde provided quinoline 11. Subsequent tosylation, reduction, silylation, and then oxidation led to aldehyde 15. The latter was subjected to a Pictet-Spengler reaction with tryptophan methyl ester that yielded product 16, and then desilylation gave the lavendamycin analogue 17. This compound was oxidized by Dess-Martin periodinane, and the cyclized derivative 18 was obtained via a hemiaminal intermediate. The same sequence from 2,4-diamino-5-methoxybenzaldehyde or from (2,4-diaminophenyl)propan-3-one led to compounds 30 and 31, or 40 and 41, respectively. (C) 2008 Elsevier Ltd. All rights reserved.