Total Synthesis of Neo??Tanshinlactones through a Cascade Benzannulation??Lactonization as the Key Step

K Ghosh, R Karmakar, D Mal

Index: Ghosh, Ketaki; Karmakar, Raju; Mal, Dipakranjan European Journal of Organic Chemistry, 2013 , # 19 p. 4037 - 4046

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Citation Number: 8

Abstract

Abstract The cascade annulation-lactonization of phthalides with α-carboxyfurylacrylates in the presence of lithium hexamethyldisilazide (LiHMDS) provides both convergent and semiconvergent regioselective syntheses of neo-tanshinlactones in moderate yields. This methodology also offers an avenue for the direct syntheses of hitherto unreported 6- alkoxycarbonyl-substituted neo-tanshinlactones and their heterocyclic analogues. A new ...