Stereoselective synthesis of (E)-,(E, Z)-and (E, E)-conjugated dienes via alkylation of 3-sulfolenes as the key step

…, H Ohsawa, T Suzuki, H Takayama

Index: Yamada, Sachiko; Ohsawa, Hideto; Suzuki, Takayoshi; Takayama, Hiroaki Journal of Organic Chemistry, 1986 ,  vol. 51,  # 25  p. 4934 - 4940

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Citation Number: 48

Abstract

A new stereoselective method is presented for synthesizing (El-,(E a-, and (E, E)-conjugated dienes via alkylation of 3-sulfolenes as the key step. Direct alkylation of 3-sulfolene at the 2- position proceeds with good yields when labile sulfolene a-carbanion is generated in the presence of alkyl iodides in THF-HMPA solution at-78" C. Alkylation of 2-alkyl-3-sulfolenes gives trans-2, 5-dialkyl-3-sulfolenes with 100% regioselectivity and more than 90% ...