Rearrangement of 3-Aryl-4-methylmorpholinium-4-methylides

Abstract

Fluoride-ion induced desilylation reaction of 3-Aryl-4-methyl-4-[(trimethylsilyl)methyl]morpholinium iodides 5a, b gave 4-methyl-6-phenyl-1,4-oxazepane (9a, Stevens rearrangement product) from 5a, and 10-methoxy-2-methyl-1,2,3,4,6, 11a-hexahydro-5,2-benzoxazonine (7b) from 5b. In the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, however, both reactions afforded 10-substituted 2-methyl-1,2,3,4,6,7-hexahydro-5,2-benzoxazonines 8a, b (Sommelet-Hauser rearrangement products)