... for 2 h. At reduced pressure the solution was evaporated to about 1/2 the original volume, a white crystalline solid 7c, 0.5 g (82%) separated, mp 116-117°C ... information see the review on the chemistry of the “Oxocarbons”, in “The Chemistry of the Carbonyl Group”, Vol. ...
![(3aS,6aS)-3a,3b,6a,6b-tetramethoxy-2,5-diphenyltetrahydrocyclobuta[1,2-d:3,4-d']bis([1,3,2]dioxaborole) Structure](https://image.chemsrc.com/caspic/448/86212-16-0.png)
![1,2:2,3:3,4:4,1-tetrakis[propylboranediylbis(oxy)]cyclobutane Structure](https://image.chemsrc.com/caspic/148/86212-11-5.png)
