Hydrosulphite lithium

The reduction of quinoline with either lithium or sodium in liquid ammonia produces only 1,4-dihydroquinoline . Formation of 1,2-dihydroisoquinolines was observed in the reduction of quaternary isoquinoline salts with sodium hydrosulphite ", lithium aluminium hydride " , NaBH4 , dialkylaluminohydrides or on treatment with a Grignard reagent . 

Moissan in 1902 obtained anhydrous hydrosulphites by passing sulphur dioxide diluted with hydrogen over the hydrides of the alkali and alkaline earth metals.6 He was able to produce the hydrosulphites of sodium, potassium, lithium, calcium and strontium in this way, and by measurement of the quantity of hydrogen liberated was able to prove the correctness of the general formula Ma.S204 ... 

Many achiral or chiral substituted382 and bridged 1,4-dihydropyridines383 have been prepared by a reduction of quaternary pyridium salts with sodium hydrosulphite as NADH models for enantioselective reduction of some prochiral substrates. A lithium aluminium hydride reduction of Af-acylenamines has also been observed384-386. 

The di-trans isomer 206 was isolated from the products of the reaction of 190 with the bisphosphonium salt 205 in the presence of lithium ethoxide. The reaction of 207 (obtained by the oxidative coupling of 206, with dimethyl sulphate followed by reduction with sodium hydrosulphite) yielded the cyclic compound, containing the dihydropyridine nucleus, 208a. Lithium aluminium hydride reduction of 207 yielded... 

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