Ando K, Takama D. Stereoselective Synthesis of Trisubstituted (
Z)-Alkenes from Ketones via the Julia-Kocienski Olefination Using 1-Methyl- and 1-
tert-Butyl-1
H-tetrazol-5-yl Alkyl Sulfones.
Org Lett 2020;
22:6907-6910. [PMID:
32820934 DOI:
10.1021/acs.orglett.0c02440]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
1-Methyl-1H-tetrazol-5-yl (MT) alkyl sulfones 1b, 3b, and 7b react with various unsymmetrical ketones in the presence of LiHMDS in THF at low temperature to give trisubstituted (Z)-alkenes in good yields stereoselectively (Z/E = 91:9 to 99:1). For sterically less demanding ketones, olefination using t-Bu reagents 1d and 3d generated (Z)-alkenes with higher stereoselectivity (93:7-99:1).
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