Novel polyoxazole-based cyclopeptides from Streptomyces sp. Total synthesis of the cyclopeptide YM-216391 and synthetic studies towards telomestatin.

A convergent, complementary, synthetic approach to the contiguously linked tris-oxazole units 10, 11 and 12 in telomestatin (1) and YM-216391 (2) is described. The route involves coupling reactions between oxazole 4-carboxylic acids, viz 16a, 16c, 16d and oxazole 2-substituted methylamines, viz 16b, 16e, 17, leading to the amides 18 and 21, followed by cyclodehydrations to the corresponding bis-oxazole oxazolines, e.g.

A flow process for the multi-step synthesis of the alkaloid natural product oxomaritidine: a new paradigm for molecular assembly.

A flow process for the multi-step synthesis of the alkaloid natural product (+/-)-oxomaritidine is described, mediated through the use of microfluidic pumping systems that progress material through various packed columns containing immobilized reagents, catalysts, scavengers or catch and release agents; our route involves the combination of seven separate synthetic steps linked into one continuous sequence utilizing flow chemistry.

Synthesis and establishment of stereochemistry of the unusual polyoxazole-thiazole based cyclopeptide YM-216391 isolated from Streptomyces nobilis.

A concise total synthesis of the unusual oxazole-based cyclopeptide structure YM-216391, which also establishes the stereochemistry of the natural product i.e. 1, is described.