Sulfides, 1,3-dienyl alkylation

Unsubstituted 2//-pyran (6) was converted to dienyl sulfide 510a along with a small amount of the methyl homolog 510b by treating with sodium in HMPTA or naphthylsodium in THF followed by alkylation with methyl iodide. The conversion probably proceeded via a short-lived anion.419... 

Dienyl sulfides, which have been otherwise efficiently alkylated at the allylic position using KNH2 or LDA as the base (Scheme 3, entries a and c) or have added -butyllithium at their 8-site (Scheme 38, entry a), - have been selectively alkylated at their a-vinylic site by use of a strong metallating base such as Bu"Li-TMEDA (Scheme 3, entry b) or Bu Li-Bu DR (Scheme 38, entry b). - ... 

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See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ , ]

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