Synthesis of 4-Alkyl- and 4-(ω-Chloroalkyl)-3-hydroxy-5-alkylidenebutenolides Based On Cyclizations of 4-Alkyl- and 4-(ω-Chloroalkyl)-1,3-bis(trimethylsilyloxy)buta-1,3-dienes with Oxalyl Chloride - Nguyen, Van Thi Hong; Bellur, Esen; Appel, Bettina; Langer, Peter (Synthesis, 2006)