ChemInform Abstract: Saturated Heterocycles. Part 124. Stereochemical Studies. Part 123. A Simple Synthesis of Condensed N-Methyl-Substituted 1,3-Oxazines.
Abstract
The previously published reaction A) of the oxazines (I) is repeated and, besides the formerly isolated p-nitrobenzaldehyde (II), the N-methyl oxazines (III) (isolated as picrates) are now found in the mother liquor.
ChemInform Abstract
The previously published reaction A) of the oxazines (I) is repeated and, besides the formerly isolated p-nitrobenzaldehyde (II), the N-methyl oxazines (III) (isolated as picrates) are now found in the mother liquor. The mechanism proposed for the formation of (III) is confirmed by reaction A) with cis- and trans-cyclohexanes (IV) yielding likewise the oxazines (III). In the case of cis-cyclopentane derivatives (VIa) and (VIIIa) and the cis- and trans-cyclohexane (X) the ring closure and N-methylation to the oxazines (VIIa), (IXa) and (XI) (isolated as picrates or hydrochlorides) takes place in good yield. The trans-cyclopentane derivatives (VIb) and (VIIIb), however, fail to react, even after a much longer reaction time.
