Skip to main content
. Author manuscript; available in PMC: 2016 Jan 19.
Published in final edited form as: Angew Chem Int Ed Engl. 2014 Dec 2;54(4):1223–1226. doi: 10.1002/anie.201410443

Table 1.

Thermal cycloaddition studies.[a,b]

graphic file with name nihms647081u1.jpg
Entry R1 Solvent Temp. (°C) Ratio 18 : 19 : 20[b]
1 OH toluene 165 1 : 0 : 0
2 OTf toluene 100 1 : 0 : 0.15
3 CO2Me heptane 100 1 : 0.9 : 0.02
4 CO2Me PhCF3 100 1 : 1.4 : 0.07
5 CO2Me MeCN 100 1 : 2.4 : 0.4
6 CO2Me DMF 100 1 : 3.1 : 0.7
[a]

Conditions: 18 (0.03 M in solvent).

[b]

Ratios determined by 1H NMR. Cycloadducts (19) were formed as an approximate 1:1 mixture of diastereomers.