Naphthothiete with methyllithium

Refluxing 2,4-diphenyl-2H-thiete 1,1-dioxide in ethanol yields the acyclic sulfone 286. Treatment of naphthothiete sulfone 205b with methyllithium, sodium hydroxide, or lithium anilide gives products, for example, 287, resulting from nucleophilic attack on the sulfur atom of the sulfone... 

Naphthothiete (34) with methyllithium (McM —McLi, Scheme 10) formed 8-lithio-l-naphthyl methyl sulfide (60, M —Li) that on taking up 1 or 2 equiv of additional 34 was converted into dimer 63 or trimer 64. Sulfide 60 at treating with water formed methyl 1-naphthyl sulfide (62). Dimer 63 was also prepared by an independent synthesis between 60 (M = MgCl) and 1-naphthyl thiochloride (61). 

The reaction of naphthosulfone (36, Scheme 11) with the lithium aluminum hydride takes two directions. The first route consists in reduction to naphthothiete (34) with subsequent transformations represented in Scheme 10 (34—>56—>57—>58 59) on quenching dilithium intermediate 57 with water (R = H). The second path involves opening the hetero ring with the nucleophile without reduction (36—>65 67) also analogous to (34 -> -> -> 59) for naphtho[l,8-Z c]thiete proper (cf. Schemes 10 and 11). Methyl naphthyl sulfone (67) thus obtained was also prepared by an independent synthesis by treating naphtho[l,8-Z c]sulfone (36) with methyllithium followed by quenching with water (36 66—>67). 

Methyllithium attacked the sulfur atom of naphthothiete 205 to give 231 and oligomers 232 and 233 via 8-mercaptomethyl-l-lithionaphthalene. Treatment with lithium aluminum hydride followed by methylation gave 234. Treatment of thiete 215 with triphenylphosphine leads to ring-expanded products possibly via nucleophilic attack by phosphorus on sulfur. ... 

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See also in sourсe #XX -- [ ]

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