A convenient synthesis of partially reduced benzo[c]phenanthrenes, its ketals and ketones

作者：Pratap Ramendra^*; Raghunandan Resmi; Mishra Abhishek Kumar; Maulik P R; Gupta V P; Ram Vishnu Ji

来源：Tetrahedron, 2010, 66(7): 1458-1464.

DOI：10.1016/j.tet.2009.12.026

• Benzo[c]phenanthrene
• 2-Oxo-4-(piperidin-1-yl)-5,6-dihydro-2H-benzo[h]-chromene-3-carbonitrile s
• Ring transformation

A concise and convenient synthesis of various partially reduced 6-sec-amino-1,2,3,4,7,8-hexahydro-, 6-sec-amino-1,2,7,8-tetrahydrobenzo[c]phenanthrene-5-carbonitriles, 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-2-one-5-carbonitrile cycloalkene ketals, pendant with electron donor and acceptor substituents has been described through base catalyzed ring transformation of 2-oxo-4-sec-amino-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles by cyclohexanone, 2-cyclohexen-1-one, 1,4-cyclohexanedione monocycloalkene ketals. The acid catalyzed deketalation of 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-2-one-carbonitrile ketals led to yield 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-3-carbonitrile-2-ones in excellent yield. We also performed the X-ray studies of the molecules 3d and 6a to know the degree of non-planarity.

• 出版日期2010-2-13