Diastereoselective Access to the Spirotetronate Subunit of the Quartromicins

Abstract

Diastereoselective Access to the Spirotetronate Subunit of the Quartromicins D i a s t e r e o s e l e c t i v e A c c e s s t o t h e S p i r o t e t r o n a t e S u b u n i t o f t h e Q u a r t r o m i c i n sAbstract: The agalacto-spirotetronate B subunit of quartromicins was synthesized in a predictible manner, following the ClaisenIreland/metathesis approach (CIM strategy). Ene-yne ring-closure and selective mismatch Sharpless dihydroxylation are discussed as key steps, allowing an efficient approach to these structures.

Spirotetronate Polyketides as Leads in Drug Discovery

“… 130 Bedel’s group offered an alternative strategy of constructing the spirotetronate subunits using RCM, but to date no total syntheses of quartromicins have been completed. 131 …”

A synergistic approach to polycyclics via a strategic utilization of Claisen rearrangement and olefin metathesis

“…The diastereoselectivity of the Ireland CR dropped when the acetylenic moiety was unprotected due to presence of a double-metallated species generated before the Ireland CR process (Scheme 49). 57 Bedel and co-workers also reported a stereoselective formal synthesis of (-)-fumagillol 303 which is a direct precursor of the anti-angiogenic sesquiterpene fumagillin. They have applied a sequence of stereoselective Ireland CR and RCM as key steps using diisopropylidenemannitol 299 as the starting material (Scheme 50).…”

Recent Progress on Enyne Metathesis: Its Application to Syntheses of Natural Products and Related Compounds

“…The agalacto -spirolactone B subunit of quartromicins has been synthesized using the Claisen-Ireland/ RCM of enyne approach by Haudrechy et al . [ 70 ]. Enyne 74 was treated with 1g in toluene at 80 °C to afford 75 in 73% yield.…”