Synthesis of β‐Keto Esters by C ‐Acylation of Preformed Enolates With Methyl Cyanoformate: Preparation of Methyl (1α,4aβ,8aα)‐2‐Oxodecahydro‐1‐Naphthoate

Abstract

Synthesis of β‐keto esters by C‐acylation of preformed enolates with methyl cyanoformate: preparation of methyl (1α,4aβ,8aα)‐2‐oxodecahydro‐1‐naphthoate product: methyl (1α,4aβ,8aα)‐2‐oxodecahydro‐1‐naphthoate

Diastereoselective Synthesis of an Advanced Intermediate of Thapsigargin and Other 6,12-Guaianolides Using a RCEYM Strategy

“…As a key strategic sequence for the viability of the approach in the case of thapsigargin and other guaianolides, two successive diastereoselective additions, an allylation at C10 and then an alkynylation reaction at C6, are envisioned to prepare 4 ( n 1 = 1) from the cyanocyclopentenyl methyl ketone 5 . For the construction of the latter, we planned a sequence similar to that used by Ciufolini et al for the synthesis of sordarin, i.e., sequential condensation of Mander’s cyanoformate for the carboxylation of 2-methyl-1,3-cyclopentanedione 7 , and cyanation with Nagata’s diethylaluminum cyanide to obtain 5 . We report here the results of our efforts for this project.…”