Table 1.

Optimization and exploration of substrate scope for tandem Wolff rearrangement/ketene addition.

catalyst	$18$ entry	yielda (%)	eeb (%)	$42$ entry	yielda (%)	eeb (%)	$43$ entry	yielda (%)	eeb (%)	$44$ entry	yielda (%)	eeb (%)	$45$ entry	yielda (%)	eeb (%)
30	1	61c	79	9	64	58	17	49	64	25	48	9	33	54	35
31	2	50	24	10	52	64	18	60	7	26	43	7	34	65	42
32	3	64	−57	11	62	−22	19	56	−51	27	48	−3	35	38	−20
33	4	67	64	12	69	50	20	59c	71	28	48	25	36	42	23
34	5	58	48	13	77c	71	21	55	−39	29	40	7	37	61	41
35	6	65	−54	14	66	0	22	54	−34	30	48	−26	38	42	−23
36	7	90	−16	15	60	−59	23	65	−7	31	47	−5	39	42c	−75
37	8	50	53	16	49	−23	24	50	37	32	31c	34	40	35	−1

^aReactions performed on 0.050 mmol scale and irradiated for 18 hours. Yield determined by ¹H NMR analysis versus an added internal standard.

^bDetermined by SFC using a chiral stationary phase.

^cReactions performed on 0.200 mmol scale and irradiated for 48 hours, isolated yield reported.