Synthesis of the Nakanishi Ring-Locked Retinoid

Table 1

Summary of the literature [1, 7] and experimental (exp) ¹H NMR chemical shifts of key resonances (δ reported in ppm) for C13-C14 E and Z-isomers of 1.

Proton	C13-C14 Z-isomer			C13-C14 E-isomer
Reference	[1]	[7]	exp	[1]	[7]	exp
Solvent	CDCl3	CDCl3	CD2Cl2	CDCl3	CDCl3	CDCl3
H-7	6.32	—	6.40	6.32	—	6.38
H-8	6.52	—	6.61	6.52	—	6.57
H-11	7.02	7.00	7.07	6.92	—	6.95
H-12				6.22	6.21	6.26
H-14	5.79	5.78	5.80	5.93	5.93	5.97
H-15	10.12	10.11	10.15	10.03	10.03	10.07