Diastereoselective allylation-based asymmetric total synthesis of 1,10-seco-guaianolides

Abstract

A Cr(II)-mediated Nozaki-Hiyama allylation of aldehydes with fuctionalized chiral allylbromolactone paved an easy access to β-hydroxy-aryl/alkyl-α-methylene-γ-butyrolacones in good yields and high diastereoselectivities. A subsequent undemanding translactonization was orchestrated in an...

Asymmetric total syntheses of aspilactonol F and aspiketolactonol and synthetic studies toward diplofuranoxin

“…The latter reaction was successfully applied to the syntheses of paraconic acids and guaianolide natural products by us and others. 19 a ,20 Unfortunately, the treatment of 2a with p -TsOH led to the deprotection of only the silyl group giving 14a (Table 2, entry 1). Furthermore, a basic hydrolysis of the lactone and then treatment with an acid for translactonization led to the decomposition of 2a (entry 2).…”