STEREOCHEMICAL STUDIES 130 SATURATED HETEROCYCLES 132; SYNTHESIS AND RING-CHAIN TAUTOMERISM OF STEREOISOMERIC 1,3-OXAZINES CONDENSED WITH THE CYCLOPENTANE RING

Article abstract of DOI:10.1016/S0040-4020(01)81498-8

Trough condensation of cis-2-hydroxymethylcyclopentylamine (3) and cis-2-aminomethylcyclopentanol (5) with aromatic aldehydes, tautomeric mixtures of 1,3-oxazines and open-chain Schiff bases were obtained.The two series of compounds (4a-f, 6a-f) gave satisfactory linear collerations corresponding to log K_x=k?⁺+log K_X=H (k=0.76+/-0.04 as shown earlier).The ring form of the corresponding trans derivatives is present in a fairly low amount, because of the strain in the trans fusion of the cyclopentane and the sixmembered hetero ring.N-Methyl substitution makes the ring form in the latter compounds stable, resulting in oxazines 12 and 14.All the cyclizations in question occurred stereospecifically.