Table 2.

Cyclization of 2a–e using 2 equiv. of BBr₃

S. No.	Substitutions					3 (%)a
	Entry	R1	R2	R3	R4
1	2a	H	OMe	H	OMe	3a (91)
2	2b	H	OMe	OMe	H	3b (72)
3	2c	OMe	OMe	H	H	3c (37)
4	2d	H	OMe	OMe	OMe	3d (42)
5	2e	H	OMe	H	H	3e (81)
6	2f	H	–OCH2O–		H	—b
7	2g	H	H	H	H	N.R.c

^aIsolated yield.

^bOnly demethylenated product was obtained.

^cNo reaction.