First total synthesis of herbarumin III

A simple formal stereoselective synthesis of Herbarumin III

“…These compounds also interacted with bovine brain calmodulin dependent enzyme cMAP phosphodiesterase. Due to interesting structural pattern and important biological properties, Herbarumin III (1) has recently become the synthetic target of the organic chemists [2][3][4][5][6][7][8][9]. In continuation of our work [10][11][12] on stereoselective synthesis of natural products we have developed a simple formal synthesis of the compound, which we would like to mention here.…”

Enantioselective Synthesis of Herbarumin III by Using a Chelation‐Controlled Reduction

“…NH 3 (50 ml) and 9 (5 g, 15.5 mmol) in dry THF (15 ml) (250 ml two-necked round-bottomed flask fitted with a cold-finger condenser at À 338). The mixture was then stirred for another 10 min at À 338 and quenched by the addition of solid NH 4 Cl, and NH 3 was then allowed to diffuse. The residue left was partitioned between H 2 O (50 ml) and Et 2 O (50 ml), and the aq.…”

“…aq. NH 4 Cl soln., the mixture extracted with AcOEt (3 Â 50 ml), the extract dried (Na 2 SO 4 ) and concentrated, and the crude product purified by CC (SiO 2 ): 4.98 g (86% over two steps) of 11. (4R,6R,7E)-6-{[(tert-Butyl)dimethylsilyl]oxy}-12-[(4-methoxybenzyl)oxy]dodec-7-en-4-ol (15).…”

“…Considering its structure and selective biological profile, herbarumin III has attracted a great deal of interest among synthetic organic chemists. Consequently, the synthesis of 1 has been reported by various research groups [4]. Herein, we report a protocol for the synthesis of herbarumin III based on an alkynide ion addition onto a chiral aldehyde and reagent-controlled synthesis.…”

Enantioselective total synthesis of (−)-microcarpalide

“…24 Similarly, fine tuning of the protection at the allylic position was required to construct the framework of herbarumin III, a fungal nonenolide, by ring-closing metathesis, either with Grubbs' first or second generation catalyst. 25 Although it cannot be excluded a priori that even a remote appendage might exert a dramatic effect in the formation of 10-membered macrocycles by RCM, this hypothesis remains undoubtedly a topic for further investigations which will have to be verified over a broader range of substrates. In this respect, the influence of remote substituents on the E/Z ratio in ring-closing metathesis has been reported for larger ring systems, such as epothilones 26 and salicylihalamides, 27 which feature a 16-and 12-membered lactone skeleton, respectively.…”