Of pseudolaric acid

Scheme 2.29 TMM [4+3 cydoadditions in the synthetic study of pseudolaric acid B (106)...

Synthesis of pseudolaric acid A was carried out by Pan et al. [54] P-keto-ester compound 7-10, on treatment with iodo-compound 7-11, potassium carbonate and 18-crown-6 in toluene gave 7-12, which was hydrolyzed to compound 7-13 in dilute acetic acid. When the compound 7-13 was treated with 0.5 equivalent of potassium t-butoxide in THF-t-BuOH (1 1) at room temperature for 1 hr, the key compound 7-14 was obtained. The tin compound 7-15, after treatment of butyl lithium, reacted with 7-14 to form the diol 7-16. Reaction of 7-16 with sodium hydride gave the 8 -lactone 7-17 (Scheme 14). The remained steps are extension of the side chain and acetylation of the hydroxyl group at C-4 for accomplishment. 

Table 6. Quantitative Activity of Pseudolaric Acid B (7-2), its Potassium Salt (7-9) and Amphotericin B Against Candidas and Torulopsis Species.

Ylid trapping was used to establish the tricyclic system 8.529 in a synthesis of pseudolaric acid (Scheme 8.142), using a chiral rhodium complex to achieve better stereoselectivity in favour of the desired isomer. ... 

Enantioselective Synthesis of (—)-Pseudolaric Acid B via an intramoiecuiar [5-1-2] Cycioaddition Reaction of a Vinyicyciopropane with an Aikyne... 

Trost et al. reported the first asymmetric total synthesis of pseudolaric acid B by exploiting a rhodium-catalyzed intramolecular [5-1-2] cycloaddition reaction of a vinylcyclopropane with an alkyne (Scheme 8.2) [4]. The vinylcyclopropane having a tethered alkyne moiety 12 was synthesized from chiral precursors 9 and 11. Treatment of 12 with a cationic rhodium(1) catalyst promoted the [5-1-2] cycloaddition reaction to form a [5.3.0]bicyclic skeleton of 13 in a diastereoselective fashion. A few steps of functional group transformations provided the alkoxycarbonyl... 

Pseudolaric acid A FIGURE 19.22 Structure of pseudolaric acid A 210. 

A total synthesis of pseudolaric acid A was reported, featuring a Sml2-mediated intramolecular alkene-ketyl radical cyclization to generate the highly functionalized cyclopentane 141 (Scheme 25.67). ° When 140 was subjected to the annulation reaction in the presence of HMPA without... 

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