FORMATION OF SPIRO INDANE DERIVATIVES FROM HYDROXY LACTAMS DERIVED FROM N-(1-PHENYLETHYL)-PHTHALIMIDE AND N-PYRIDINE-2,3-DICARBOXIMIDE

Spiro[indane-1,7'-pyrrolo[3,4-b]pyridin]-5'-ones 18-22 are formed by a cid-catalysed rearrangement from nylethyl)-6,7-dihydropyrrolo[3,4-b]py ridin-5-ones. Further spiro indanes 39, 43 and 44 and spiro naphthalen es 41, 42, 45 and 46 are obtained from lkyl)-3-hydroxy-2-(1-phenylethy l)isoindolin-1-ones or from mega-phenylalkyl)-7-hydroxya-6-(1-phenylet yl)-6,7- dihydropyrrolo [3,4-b] pyridin-5-ones via alpha,alpha-cyclisa tion of N-acyliminium ion intermediates.