摘要:
The lithium aluminum hydride reduction of 7-methoxychromanone oxime (I) and 7-methoxy-3-methylchromamone oxime (II) gave only the rearrangement product (the 2,3,4,5-tetrahydro-1,5-benzoxazepine derivative). 7-Methoxy-2-methylchromanone oxime (III) and 7-methoxy-2-isopropylchromanone oxime (IV) gave a mixture of the rearrangement product (secondary amine) and the normal reduction product (primary amine). 7-Methoxy-2-t-butylchromanone oxime (V) gave only the normal reduction product. The main conclusions to be drawn from these results are as follows: (1) The chromanone oximes without a C2 substituent give only the rearrangement product. (2) The chromanone oximes with a C2 substituent give a mixture of the normal reduction product and the rearrangement product. (3) The more bulky substituent at C2 gives the more normal reduction product and the smaller quantity of the rearrangement product.