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Synthesis of functionalized cyclic enamines from lithium alkylphenyl sulfones and N ‐carbo‐ tert ‐butoxy lactams
Author(s) -
Arias Luis A.,
Arbelo David,
Alzérreca Arnaldo,
Prieto José A.
Publication year - 2001
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570380104
Subject(s) - synthon , chemistry , lithium (medication) , piperidine , stereochemistry , alkyl , medicinal chemistry , organic chemistry , medicine , endocrinology
Alkylphenyl sulfones 3 are appropriate synthons for the synthesis of 2‐phenylsulfonyl alkylidene pyrro‐lidine or piperidine derivatives 1 in good to moderate yields. The lithium alkyl sulfones 4 are first reacted with the desired protected lactams and then subjected to acidic methanolysis to afford the unusual enam‐ines 1a‐e . NMR studies (COSY 1 H‐ 1 H, COSY 1 H‐ 13 C, NOE) showed the Z enamines to exist in a dynamic equilibrium with the corresponding imines 2 . The stereochemistry of the described compounds was confirmed by molecular calculations.