Photochemical reactions of 2,6-bis(trimethylsilyl)-4H-pyran with α-ketoesters
摘要:
The photochemical reaction of 2,6-bis(trimethylsilyl)-4H-pyran with various alpha-ketoesters gave moderate to good yields of new bis(silylated) 4H-pyrans functionalized in position 4. In some cases, an oxidation by-product was also isolated. (C) 2000 Elsevier Science Ltd. All rights reserved.
The new 2,6-bis-trialkylsilyl-4H-pyranes were easily prepared from 1,5-bisdithianes via a two steps sequence of dethioketalization and cyclodehydration in the presence of a catalytic amount of p-toluenesulfonic acid. (C) 1999 Elsevier Science Ltd. All rights reserved.