PDF《Supporting Information》

1 H-NMR (CDCl3, 400MHz): δ 6.6-6.8 (s,1H), 6-6.13 (s, 1H), 1.83-1.95 ( s, 3H), 1.17- 1.28 (s, 6H).

7 Mass Spectral data: m/e (relative intensity):

284 (M+ 7),

205 (1),

177 (0.5),

153 (6),

151 (87),

123 (11),

107 (7),

95 (100),

84 (40),

67 (27),

55 (38),

40 (24). Step

2 Methoxy carbonylation of the vinyl triflate: To a solution of Pd(OAc)2 (176mg, 0.8mmol), triphenylphosphine (444mg, 1.7mmol), diisopropylethylamine (Huning'

s base, 4.5ml, 26mmol) and methanol (20mL) in dry DMF( 50ml) under a dry nitrogen atmosphere, was added 2g of the vinyl triflate isolated from the previous reaction. A stream of CO was bubbled through the solution for

20 mins and stirred with a CO balloon for

12 hours. Standard workup with ether and water gave black oil after the removal of solvent. Flash chromatography (silica gel, 12% ether in petroleum ether) gave the product as a pale yellow liquid (1.33g).

1 H-NMR (CDCl3, 400MHz): δ 7.2-7.4 (d, 1H), 6.4-6.65 (d, 1H), 3.66-3.91 (s, 3H), 1.8- 2.1 (d, 3H), 1.25-1.35(s,6H). Mass Spectral data: m/e (relative intensity):

194 (M+ ,95),

179 (17),

162 (20),

151 (68),

135 (48),

134 (75),

124 (23),

107 (78),

91 (100),

79 (28),

77 (26),

65 (30),

52 (16),

43 (28),

39 (33). Step 3: Hydrolysis of ester to acid: The ester obtained in the above step was stirred with 10% LiOH solution in methanol water mixture for 8-12 hours. Methanol was removed under vacuum and added cold water to this mixture and acidified with dilute hydrochloric acid to precipitate the acid. The acid was filtered, dried and s........