Domino [3+3] Annulation/Ring-Cleavage Reactions of 1,3-Bis(trimethylsilyloxy)-1,3-butadienes with 5-Aryl- and 5-Vinyl-3-acyl- 4,5-dihydrofurans: Efficient Synthesis of 5-(4-Chlorobut-2-en-1-yl)- and 5-(2-Aryl-2-chloroethyl)salicylates
The domino “[3+3] cyclization–ring-opening” reactions of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-acetyl-5-vinyl-4,5-dihydrofurans afforded 5-(4-halobut-2-en-1-yl)salicylates. The reactions of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-acetyl-5-aryl-4,5-dihydrofurans gave 5-(2-aryl-2-chloroethyl)salicylates.