Dioxan 2,5-diethoxy

Bis-[2-methyl-propyl -amino) -5,5-dimethyl-l, 3-dioxan 2- (Dicyclohexylammo ) -5,5-dimethyl-l, 3-dioxan 5,5-Dimethyl-2-(N-methyl-anilino)-l,3-dioxan 2-Dibenzylamino-5,5-dimethyl-l, 3-dioxan Diethoxy- f N-methyl-anilino) -methan Diethoxy-diphenylamino-methan... 

The alkynylation of estrone methyl ether with the lithium, sodium and potassium derivatives of propargyl alcohol, 3-butyn-l-ol, and propargyl aldehyde diethyl acetal in pyridine and dioxane has been studied by Miller. Every combination of alkali metal and alkyne tried, but one, gives the 17a-alkylated products (65a), (65c) and (65d). The exception is alkynylation with the potassium derivative of propargyl aldehyde diethyl acetal in pyridine at room temperature, which produces a mixture of epimeric 17-(3, 3 -diethoxy-T-propynyl) derivatives. The rate of alkynylation of estrone methyl ether depends on the structure of the alkyne and proceeds in the order propar-gylaldehyde diethyl acetal > 3-butyn-l-ol > propargyl alcohol. The reactivity of the alkali metal salts is in the order potassium > sodium > lithium. 

R = COOH).34 On the other hand, controlled conversion into the aldehyde is also possible. Thus aldehyde (241) was obtained by the action of selenium dioxide in boiling dioxane on 3,8-diethoxy carbonyl-amino-6-methylphenanthridine,324 and 6-formylphenanthridine N-oxide has been obtained in good yield by oxidising the 6-methyl compound with selenium dioxide in pyridine.298... 

Acetyl-3,6-diethoxy-5-isopropyl-2-methyl-2,5-dihydropyrazine (20) gave potassium 3,6-diethoxy-5-isopropyl-2-methyl-2,5-dihydro-2-pyrazinecarboxylate (21, R = K) (KOC1, dioxane—H20,4 — 20°C, 1 h cmde) that was characterized as the corresponding ester, methyl 3,6-diethoxy-5-isopropyl-2-methyl-2,5-dihydro-2-pyrazinecarboxylate (21, R = Me) (Mel, THF, 0°C, 48 h 46% overall).170,371... 

---