Table 1. Optimization of conditions for segmented flow reduction/hydrolysis/cyclo-condensation sequence.

Entry	Coil 1, t R/min	Coil 2, T/°C	Equiv. of HCl	Yield a (%)
1	2.5	100	5.5	21
2	2.5	140	5.5	46
3 b	2.5	140	5.5	45
4	6	140	5.5	71 (69)
5	10	140	5.5	67
6	18	140	5.5	62
7	35	140	5.5	58
8	6	100	5.5	21
9	6	120	5.5	55
10	6	160	5.5	53
11 c	6	140	5.5	70
12 d	6	140	5.5	71
13	6	140	0	35
14	6	140	2.2	68
15	6	140	11	58

^aYield determined from quantitative ¹H NMR analysis with DMF as internal standard, yield of isolated product in parentheses.

^b63 minute residence time in reactor coil 2.

^c2.2 equivalents of dione used.

^d2 equivalents of ascorbic acid used.